Android系统外文翻译
外文翻译安卓系统的大体描述
附录二外文文献（原文）The basic of description of android system The mainstream of the next generation of open operating systems will not be on the desktop, but will appear in the phone that we carry every day. Open environment will lead these new applications may be integrated into these online services that already exist, of course, as with growing data services on mobile phones support the security flaws on the phone is also becoming increasingly clear. The nature of the next-generation operating system, whether to provide a complete integrated security platform.By the Open Mobile Alliance (open Handset Alliance led by Google) developed the android system is a widely optimistic about an open source phone system, the system provides a basic operating system, a middle ware application layer, a java development tools and a system Application collector (collection of system applications). The android the SDK since 2007 on the release of the first android phone in October 2020 before the birth. Google opened since then on his own time, Taiwan's HTC, the manufacturer of the T-Mobile G1 estimate G1 shipments have more than one million at the end of 2020. According to industry insiders expect the G1 mobile phone sales in 2020 continue. Many other mobile phone suppliers in the near future plans to support this system.Around an android and a huge developer community has beenestablished, while a lot of new products and applications on the android. Android's main selling point is that it enables developers to seamlessly expand online services to mobile phones. This is the most obvious example is Google's tightly integrated with Gmail, Calendar and Contacts Web applications through the system. Users only need to provide an android user name and password, the phone automatically sync with Google services. The other vendors are quickly adapt their existing instant messaging, social networking and gaming services. Android and many companies find new ways to integrate their existing business to the android.Traditional desktop and server operating system has been working for the integration of security features. These individuals and business applications on a single platform is very good, however a business phone platform like android is not very useful. It gives the hope of many researchers. Android is not parked in the body for other platform application support: the implementation of the application depends on a top-level JAVA middle ware, the middle ware running on the embedded Linux kernel. Therefore, developers should deploy their applications to the Android must use a custom user interface environment.In addition, the android system applications limit the application to call each other API collaboration, and the other to authenticate the user application. Although these applications have certain safety features,some of our experienced developers to create Android applications who revealed that the design of security applications is not always straight forward. Android uses a simple permission label distribution mode to restrict access to resources, but the reasons for the necessity and convenience of other applications, the designers have increased the confusion on this system. This paper attempts to explain the complexity of the Android security, and pay attention to some of the possible development defects and application security. We try to draw some lessons learned, and hope that the safety of the future.Android application framework for developers is a mandatory framework. It does not have a main () function function or a single entry point for the implementation of the contrary, the developer must in the design of application components. We developed applications to help the API of the android sdkThe Android system defines four kinds of component type.Activity component that defines the application user interface. Usually, the application developer defines each activity screen. Activity can start, it may pass and return values. Can be handled at a time only a keyboard system Activity, all other Activity will be suspended at this time.Service components perform background processing. The need for some operations when an activity, after the disappearance of the user interface (such as downloading a file or playing music), it usually takesuch action specially designed services. Developers can also use a special daemon at system startup, the service is usually defined a remote procedure call (RPC), and other system components can be used to send the interface command and retrieve data, as well as to register a callback function.ContentProvider component storage and share data with relational database interfaces. Each Content supplier has an associated "rights" to describe its contents contains. Other components when used as a handle to execute SQL queries (eg SELECT, INSERT, or DELETE content. Content suppliers are typically stored the values on the database records, data retrieval is a special case, the file is also shared by the content provider interface.The components of the broadcast receiver as to send a message from the mailbox to the application. Typically, the broadcast message, the application code implicit destination. Therefore, the radio receiver subscribe to these destinations receive messages sent to it. The application code can also be solved explicitly broadcast receivers, including the name space allocation.The main mechanism of the interaction of the components of the Component Interaction, is an intent, which is a simple message object, which contains a destination address and data components. The Android API defines his approach into intent, and use that information to initiatean activity such as start an activity (startActivity (An intent)) start services (the startService (An intent)) and radio (sendBroadcast (An intent)). Android framework to inform the calls to these methods began to perform in the target application code. This process, the internal components of communication is called an action. Simply put, the Intent object defined in the "Intent to implement the" action ". One of the most powerful features of the Android is allowed a variety of intent addressing mechanism. The developer can solve the space of a target component using its applications, they can also specify an implicit name. In the latter case, the system determines the best components of an action by considering the installed applications and user choice.Implicit name is called the action string because of his special type of the requested action. Such as a view action string, in an intent data field points to an image file, the system will directly referring to the preferred image viewer.Developers can also use the action string a large number of radio to send and receive. Receiver at the receiving end, the developers use an intent filter to customize the special action string. Android Department, including the additional goal of the resolution rules, but an optional string type of data manipulation is the most common.Android applications are written in the Java programming language.The compiled Java code —along with any data and resourcefiles required by the application —is bundled by the apt tool into an Android package,an archive file marked by an .apk suffix.This file is the vehicle for distributing the application and installing it on mobile devices;it's the file users download to their devices.All the code in a single.apk file is considered to be one application.In many ways,each Android application lives in its own world:（1）By default,every application runs in its own Linux process.Android starts the process when any of the application's code needs to be executed,and shuts down the process when it's no longer needed and system resources are required by other applications.（2）Each process has its own virtual machine(VM),so application code runs in isolation from the code of all other applications.（3）By default,each application is assigned a unique Linux user ID.Permissions are set so that the application's files are visible only to that user and only to the application itself —altough there are ways to export them to other applications as well.It's possible to arrange for two applications to share the same user ID,in while case they will be able to see each other's files.To conserve system resources,applications with the same ID can also arrange to run in the same Linux process,sharing the same VM.Application ComponentsA central feature of Android is that one application can make use ofelements of other application (provided those application permit it).For example,if your application needs to display a scrolling list of images and another application has developed a suitable scroller and made it available to others,you can call upon that scroller to do the work,rather than develop your own.Your application doesn't incorporate the code of the other application or link to it.Rather,it simply starts up that piece of the other application when the need arises.For this to work,the system must be able to start an application process when any part of it is needed,and instantiate the Java objects for that part.Therefore,unlike applications on most other systems,Android applications don't have a single entry point for everything in the application(no main()function,for example).Rather,they have essential components that the system can instantiate and run as needed.There are four types of components:ActivitiesAn activity presents a visual user interface for one focused endeavor the user can undertake.For example,an activity might present a list of menu items users can choose from or it might display photographs along with their captions.A text messaging application might have one activity that shows a list of contacts to send messages to,a second activity to write the message to the chosen contact,and other activities to review old messages or change or change settings.Tough they worktogether to form a cohesive user interface,each activity is independent of the others.Each one is implemented as a subclass of the Activity base class.An application might consist of just one activity or,like the text messaging application just mentioned,it may contain several.What the activities are,and how many there are depends,of course,on the application and its design.Typically,one of the activities is marked as the first one that should be presented to the user when the application is launched.Moving from one activity to another is accomplished by having the current activity start the next one.Each activity is given a default window to draw in.Typically,the window fills the screen,but it might be smaller than the screen and float on top of other windows.An activity can also make use of additional windows —for example,a pop-up dialog that calls for a user response in the midst of the activity,or a window that presents users with vital information when they select a particular item on-screen.The visual content of the window is provided by a hierarchy of views —objects derived from the base View class.Each view controls a particular rectangular space within the window.Parent views contain and organize the layout of their children.Leaf views(those at the bottom of the hierarchy)draw in the rectangles they control and respond to user actions directed at that space.Thus,views are where the activity'sinteraction with the user takes place.For example,a view might display a small image and initiate an action when the user taps that image.Android has a number of ready-made views that you can use —including buttons,text fields,scroll bars,menu items,check boxes,and more.A view hierarchy is placed within an activity's window by the Activity.setContentView()method.The content view is the View object at the root of the hierarchy.(See the separate User Interface document for more information on views and the hierarchy.)ServicesA service doesn't have a visual user interface,but rather runs in the background for an indefinite period of time.For example,a service might play background music as the user attends to other matters,or it might fetch data over the network or calculate something and provide the result to activities that need it.Each service extends the Service base class.A prime example is a media player songs from a play list.The player application would probably have one or more activities that allow the user to choose songs and start playing them.However,the music playback itself would bot be handled by an activity because users will expect the music to keep the music going,the media player activity could start a service to run in the background.The system would then keep themusic playback service running even after the activity that started it leaves the screen.It's possible to connect to (bind to)an ongoing service(and start the service if it's not already running).While connected,you can communicate with the service through an interface that the service exposes.For the music service,this interface might allow users to pause,rewind,stop,and restart the playback.Like activities and the other components,services run in the main thread of the application process.So that they won't block other components or the user interface,they often spawn another thread for time-consuming tasks(like music playback).See Processes and Thread,later.Broadcast receiversA broadcast receiver is a component that does nothing but receive and react to broadcast announcements.Many broadcasts originate in system code —for example,announcements that the timezone has changed,that the battery is low,that a picture has been taken,or that the user changed a language preference.Applications can also initiate broadcasts — for example,to let other applications know that some data has been downloaded to the device and is available for them to use.An application can have any number of broadcast receivers to respond to respond to respond to any announcements it considers important.All receivers extend the BroadcastReceiver base class.Broadcast receivers do not display a user interface.However,they may start an activity in response to the information they receive,or they mayuse the NotificationManager to alert the user.Notifications can get the user's attention in various ways — flashing the backlight,vibrating the device,playing a sound,and so on,They typically place a persistent icon in the status bar,which users can open to get the message.Content providersA content provider makes a specific set of the application's data available to other applications.The data can be stored in the file system,in an SQLite database,or in any other manner that makes sense.The content provider extends the ContentProvider base class to implement a standard set of methods that enable other applications to retrieve and store data of the type it controls.However,applications do not call these methods directly.Rather they use a ContentResolver object and call its methods instead.A ContentResolver can talk to any content provider;it cooperates with the provider to manage any interprocess communication that's involved.See the separate Content Providers document for more information on using content providers.Whenever there's a request that should be handled by a particular component,Android makes sure that the application process of the component is running,starting it if necessary,and that an appropriate instance of the component is available,creating the instance if necessary.Activating components:intentsContent providers are activated when they're targeted by a request from a ContentResolver.The other three components —activities,services,and broadcast receivers —are activated by asynchronous messages called intents.An intent is an Intent object that holds the content of the message.For activities and services,it names the action being requested and specifies the URI of the data to act on,amongother things.For example,it might convey a request for an activity to present an image t the user or let the user edit some text.For broadcast receivers,the Intent object names the action being announced.For example,it might announce to interested parties that the camera button has been pressed.There are separate methods for activating each type of component:1.An activity is launched(or given something new to do)by passing an Intent object to Context.startActivity() or Activity.startActivityForResult().The responding activity can look at the initial intent that caused it to be launched by calling its getIntent() method.Android calls the activity's onNewIntent()method to pass it any subsequent intents.One activity often starts the next one.If it expects a result back from the activity it's starting,it calls startActivityForResult() instead of startActivity().For example,if it starts an activity that lets the user pick a photo,it might expect to be returned the chosen photo.The result is returned in an Intent object that's passed to the calling activity's onActivityResult() method.2.A service is started(or new instructions are given to an ongoing service)by passing an Intent object to Context.startService().Android calls the service's onStart() method and passes it the Intent object.Similarly,an intent can be passed to Context.bindService() to establish an ongoing connection between the calling component and a target service.The service receives the Intent object in an onBind() call.(If the service is not already running,bindService() can optionally start it.)For example,an activity might establish a connection with the music playback service mentioned earlier so that it can provide the user with the means(a user interface)for controlling the playback.The activity would call bindService() to set up that connection,and then call methods defined by the service to affect the playback.A later section,Remote procedure calls,has more details about binding to a service.3.An application can initiate a broadcast by passing an Intent object to methods like Context.sendStickyBroadcast() in any of their variations.Android delivers the intent to all interested broadcast receivers by calling their onReceive() methods.For more on intent messages,see the separate article,Intents and Intent Filters.Shutting down componentsA content provider is active only while it's responding to a request from a ContentResolver.And a broadcast receiver is active only while it's responding to a broadcast message.So there's no need to explicitly shut down these components.Activities,on the other hand,provide the user interface.They're in a long-running conversation with the user and may remain active,even when idle,as long time.So Android has methods to shut down activities and services in an orderly way:1.An activity can be shut down by calling its finish() method.Onte activity can shut down another activity (one it started with startActivityForResult())by calling finishActivity().2.A service can be stopped by calling its stopSelf() method,or by calling Context.stopService().Components might also be shut down by the system when they are no longer being used or when Android must reclaim memory for more active components.A later section,Component Lifecycles,discusses this possibility and its ramifications in more detail.The manifest fileBefore Android can start an application component,it must learn that the component exists.Therefore,applications declare their components in a manifest file that's bundled into the Android package,the .apk file that also holds the application's code,files, and resources.The manifest is a structured XML file and is always named AndroidManifest.xml for all applications.It does a number of things in addition to declaring the application's components,such as naming any libraries the application needs to be linked against(besides the default Android library)and identifying any permissions the application expects to be granted.But the principal task of the manifest is to inform Android about the application's components.For example,an activity might be declared as follows:The name attribute of the <activity>element names the Activity subclass that implements the activity.The icon and label attributes point to resource files containing an icon and label that can be displayed to users to resource files containing an icon and label that can be displayed to users to represent the activity.The other components are declared in a similar way —<service>elements for services,<receiver>elements for broadcast receivers,and<provider>elements for content providers.Activities,services,and content providers that are not declared in the manifest are not visible to the system and are consequently never run.However,broadcast receivers can either be declared in themanifest,or they can be created dynamically i code (as BroadcastReceiver objects)and registered with the system by calling Context.registerReceiber().For more on how to structure a manifest file for your application,see The Android Manifest.xml File.Intent filtersAn Intent object can explicitly name a target component.If it does,Android finds that component(based on the declarations in the manifest file)and activates it.But if a target is not explicitly named,Android must locate the best component to respond to the intent.It does s by comparing the Intent object to the intent filters of potential targets.A component's intent filters inform Android of the kinds of intents the component is able to handle.Like other essential information about the component,they're declared in the manifest.Here's an extension of the previous example that adds two intent filters to the activity:The first filter in the example — the combination of the action "android.intent.action.MAIN"and the category "UNCHER"—is a common one.It marks the activity as one that should be represented in the application launcher,thescreen listing applications users can launch on the device.In other words,the activity is the entry point for the application,the initial one users would see when they choose the application in the launcher.The component can have any number of intent filters,each one declaring a different set of capabilities.If it doesn't have any filters,it can be activated only by intents that explicitly name the component as the target.For a broadcast receiver that's created and registered in code,the intent filter is instantiated directly as an IntentFilter object.All other filters are set up in the manifest.For more on intent filters,see a separate document, Intents and Intent Filters.附录三外文文献（译文）安卓系统的大体描述下一代开放操作系统的主流将可不能在桌面上，可是将会出此刻咱们天天携带的电话上。
android手机操作系统中英文对照
android⼿机操作系统中英⽂对照general 常规silent mode 静⾳模式 (silence all sounds except media & alarms 对所有⾮多媒体声⾳进⾏静⾳处理)vibrate 震动(always 始终 / never ⼀律不 / only in silent mode 仅在静⾳模式下来电震动 / only whe n not in silent mode 仅在⾮静⾳模式下来电震动)volume ⾳量 (use incoming call volume for notifications 将来电⾳量⽤作通知⾳量)incoming calls 来电phone ringtone ⼿机铃声notification 通知notification ringtone 通知铃声feedback 反馈audible touch tones 按键操作⾳(play tones when using dial pad 使⽤拨号键盘时播放按键⾳效) audible selection 选择操作⾳(play sound when making screen selcction 进⾏屏幕选择时播放⾳效)sereen lock sounds 屏幕锁定操作⾳(play sound when locking and unlocking the screen 锁定和解锁屏幕时播放声⾳)haptic feedback 触感 (vibrate when pressing soft keys and on certain UI interactions 按软键以及进⾏某些UI交互时震动)display 显⽰brightness 亮度(automatic brightness ⾃动调节亮度)auto-rotate screen ⾃动旋转屏幕animation 动画(no window animations are shown 不显⽰窗⼝动画 - (no animations ⽆动画 / some animationgs 部分动画 / all animations 所有动画))screen timeout 屏幕超时(adjust the delay before the screen automatically turns off 调整屏幕⾃动锁定前的延时)number of home panels 屏幕个数 (adjust the number of panels on home screen 调整主屏的屏幕个数)location & security 位置和安全my location 我的位置use wireless network 使⽤⽆线⽹络(location determined by Wi-Fi and/or mobile networks 通过W i-Fi和/或移动⽹络确定的位置)use GPS satellites 使⽤GPS卫星(locate to street-level(requires more battery plus view of sky) 定位时，精确度设定为街道级别（取消选中可节约电量）)phone lock ⼿机锁定phone lock settings ⼿机锁定设置phone lock type ⼿机锁定类型(phone lock is off 关闭⼿机锁定功能(none ⽆ / password 密码 / p attern 图案))change unlock password timeout 更改解锁密码超时时间use visible pattern 使⽤图案use tactile feedback 使⽤触感screen unlock 屏幕解锁set up screen lock 设置屏幕锁定(lock screen with a pattern,PIN,or password 使⽤图案、PIN或密码锁定屏幕)none ⽆(disable screen unlock security 停⽤屏幕锁定保护功能)pattern 图案(draw pattern to unlock screen 绘制图案给屏幕解锁)PIN (enter a number PIN to unlock screen 输⼊数字PIN给屏幕解锁)password 密码(enter a password to unlcok screen 输⼊密码给屏幕解锁)SIM card lock SIM卡锁定set up SIM card lock 设置SIM卡锁定lock SIM card 锁定SIM卡(require PIN to phone 需要输⼊PIN才能使⽤⼿机)change SIM PIN 更改SIM卡PINpassword 密码visible passwords 密码可见(show password as you type 输⼊密码时可见)device administration 设备管理select device admindtrators 学则设备管理器(add or remove device administrators 添加或删除设备管理器)(no available device administrators 没有可供显⽰的设备管理器)credential stronge 凭证存储use secure credentials 使⽤安全凭证(allow applications to access secure certificates and other credentials 允许应⽤程序访问安全凭证和其他凭证)install from SD card 从SD卡安装(install encrypted certificates from SD card 从SD卡安装加密的证书)(no certificate file found in the SD card 在SD卡上找不到证书⽂件)set password 设置密码(set or change the credential storage password 设置或更改凭证存储密码) (set a password for the credenntial storage(at least 8 characters) 设置凭证存储密码（⾄少8个字符） / n ew password 新密码 / confirm new password 确认新密码)clear storage 清楚存储(clear credential storage of all contents and reset its password 清楚所有内容的凭证存储并重置其密码)applications 应⽤程序unknown sources 未知来源(allow installation of non-Market applications 允许安装⾮电⼦市场提供的的应⽤程序)quick launch 快速启动(set keyboard shortcuts to launch applictions 设置快捷键启动程序)(no shortc ut 没有快捷键)manage applicatings 管理应⽤程序(manage and remove installed applications 管理和删除按章的应⽤程序)(sort by size 按⼤⼩排序)running services 正在运⾏的服务(view and control currently running services 查看和控制当前正在运⾏的服务)development 开发(set options for application development 设置应⽤程序开发选项)USB debugging USB调试(debug mode when USB is connected 连接USB后启⽤调试模式)stay awake 保持唤醒状态(screen will never sleep while charging 充电时屏幕不会休眠)allow mock locations 允许模拟地点(allow mock locations 允许模拟地点)accounts & sync 账户与同步 (add account 添加账户)general sync settings 常规同步设置background data 背景数据(applications can sync,send,and receive data at any time 应⽤程序随时可以同步、发送和接收数据)auto-sync ⾃动同步(applications sync data automatically 应⽤程序⾃动同步数据)manage accounts 管理账户(remove account 删除账户)data & synchronization 数据与同步sync contacts 同步联系⼈ (touch to sync now 触摸可⽴即同步)sync gmail 同步Gmailsync calendar 同步⽇历privacy 隐私权backup and restore 备份和还原back up my data 备份我的数据(back up my settings and other apppliction data 备份我的设置和其他应⽤程序数据)automatic restore ⾃动还原 (if I reinstall an application,restore backed up settings or other data 重新安装某个应⽤程序后，系统会还原已经备份的设置或其他数据)personal data 个⼈数据factory data reset 恢复出⼚设置(erases all data on phone 清除⼿机上的所有设置)SD card & phone storage SD卡和⼿机内存SD card SD卡total space 总容量available space 可⽤空间unmount/mount SD card 卸载/安装SD卡(unmount the SD card for safe removal 必须先卸载SD卡，才能将其安全移除)format SD card 格式化SD卡 (format(erase)the SD card 格式化（清除）SD卡)internal phone storage ⼿机内存available space 可⽤空间language & keyboard 语⾔和键盘select language 选择语⾔multi-touch keyboard 多点触摸键盘input languages 输⼊语⾔(slide finger on spacebar to change language 在空格键滑动⼿指可更改语⾔)on-screen keyboard 屏幕键盘show suggestions 显⽰建议(display corrections and completions while typing 输⼊时启⽤联想提⽰)auto-correct errors ⾃动纠错(spacebar and punctuation automatically insert highlighted wordFriday / Fri. 星期五Saturday / Sat. 星期六Sunday / Sun. 星期⽇。
Android外文文献翻译
An droid Applicati on Fun dame ntalsAn droid applicatio ns are writte n in the Java program ming Ian guage. The An droid SDK tools compile the code— along with any data and resource file—into an An droid package, an archive file with an .apk suffix. All the code in a single .apk file is considered to be one applicatio n and is the file that An droid-powered devices use to in stall the applicatio n.Once in stalled on a device, each An droid applicati on lives in its own security san dbox:The An droid operati ng system is a multi-user Linux system in which each applicatio n is a differe nt user.By default, the system assigns each application a unique Linux user ID (the ID is used only by the system and is unknown to the application). The system sets permissions for all the files in an application so that only the user ID assigned to that application can access them.Each process has its own virtual machine (VM), so an application's code runs in isolation from other applicati ons.By default, every applicatio n runs in its own Linux process. An droid starts the process whe n any of the applicati on's comp onents n eed to be executed, the n shuts dow n the process whe n it's no Ion ger n eeded or whe n the system must recover memory for other applicati ons. In this way, the An droid system impleme nts thepri nciple of least privilege. That is, each application, by default, has access only to the components that it requires to do its work and no more. This creates a very secure en vir onment in which an applicati on cannot access parts of the system for which it is not give n permissi on.However, there are ways for an applicati on to share data with other applicati ons and for an applicati on to access system services:It's possible to arrange for two applicati ons to share the same Linux user ID, in which case they are able to access each other's files. To con serve system resources, applicati ons with the same user ID can also arrange to run in the same Linux process and share the same VM (the applications must also be signed with the same certificate).An applicatio n can request permissi on to access device data such as the user's con tacts, SMS messages, the mountable storage (SD card), camera, Bluetooth, and more. All applicatio n permissi ons must be gran ted by the user at in stall time.That covers the basics regardi ng how an An droid applicati on exists withi n the system. The rest of this docume nt in troduces you to:1、The core framework components that define your application.2、The manifest file in which you declare components and required device features for your applicati on.3、Resources that are separate from the application code and allow your application to gracefully optimize its behavior for a variety of device con figurati ons.Applicati on Comp onentsApplicatio n comp onents are the esse ntial build ing blocks of an An droid applicati on. Each comp onent is a differe nt point through which the system can en ter your applicati on. Not all comp onents are actual entry points for the user and some depe nd on each other, but each one exists as its own entity and plays a specific ro—each one is a unique building block that helps define your application's overall behavior.There are four differe nt types of applicati on comp onen ts. Each type serves a disti net purpose and has a distinct lifecycle that defines how the component is created and destroyed.Here are the four types of applicati on comp onen ts:ActivitiesAn activity represe nts a sin gle scree n with a user in terface. For example, an email application might have one activity that shows a list of new emails, another activity to compose an email, and another activity for reading emails. Although the activities work together to form a cohesive user experie nee in the email applicati on, each one is in depe ndent of the others. As such, a different application can start any one of these activities (if the email application allows it). For example, a camera application can start the activity in the email applicati on that composes new mail, in order for the user to share a picture.An activity is implemented as a subclass oActivity and you can leann more about it in the Activities developer guide.ServicesA serviceis a comp onent that runs in the backgro und to perform long-running operatio nsor to perform work for remote processes.A service does not provide a user in terface. Forexample, a service might play music in the background while the user is in a different application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to it in order to in teract with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider man ages a shared set of applicati on data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the An droid system provides a content provider that man ages the user's con tact in formati on. As such, any applicati on with the proper permissi ons can query part of the content provider (such a Con tactsC on tract.Data) to read and write in formati on about a particular pers on.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save no tes.A content provider is implemented as a subclass o ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more in formati on, see the Co ntent Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announ ceme nts. Many broadcasts orig in ate from the system— for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts-for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user in terface, they may reate a status bar notificati on to alert the user whe n a broadcast eve nt occurs. More com monly, though, a broadcast receiver is just a "gateway" to other comp onents and is inten ded to do a very mini mal amount of work. For in sta nee, it might in itiate a service to perform some work based on the eve nt.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.application, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to itin order to interact with it.A service is implemented as a subclass of Service and you can learn more about it in the Services developer guide.Content providersA content provider manages a shared set of application data. You can store the data in the file system, an SQLite database,on the web, or any other persistent storage location your application can access. Through the content provider, other applications can query or even modify the data (if the content provider allows it). For example, the Android system provides a content provider that manages the user's contact information. As such, any application with the proper permissions can query part of the content provider (such a C s ontactsContract.Data ) to read and write information about a particular person.Content providers are also useful for reading and writing data that is private to your application and not shared. For example, the Note Pad sample application uses a content provider to save notes.A content provider is implemented as a subclass of ContentProvider and must implement a standard set of APIs that enable other applications to perform transactions. For more information, see the Content Providers developer guide.Broadcast receiversA broadcast receiver is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. Applications can also initiate broadcasts—for example, to let other applications know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may create a status bar notification to alert the user when a broadcast event occurs. More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work. For instance, it might initiate a service to perform some work based on the event.。
安卓系统刷机界面英文翻译大全，刷机必备！
安卓系统刷机界面英文翻译大全，刷机必备！-reboot system now 重启系统-apply update f rom ADB 从ADB进行更新。
ADB驱动是Android设备(如手机)连接PC时所需要的应用程序。
-apply updata from internal sdcard 使用手机内存中的刷机包-apply updata from external sdcard 使用手机扩展SD卡中的刷机包-apply sdcard:update.zip 使用SD卡根目录的update.zip更新系统-wipe data/factory reset 清空data分区并恢复出厂设置-wipe cache partition 清空cache（高速缓存）分区-install zip from sdcard 从SD卡选择文件更新系统--apply sdcard:update.zip 使用SD卡根目录的update.zip 更新系统--choose zip from sdcard 从SD卡选择zip格式升级包--toggle signature verification 切换签名验证--toggle script asserts 切换升级脚本检查-backup and restore 备份和恢复--Backup 备份--Restore 恢复--Advanced Restore 高级恢复-mounts and storage 挂载和存储--mount /system 挂载/system分区（系统分区）--mount /data 挂载/data分区（数据分区）--mount /cache 挂载/cache分区（缓存分区）--mount /sd-ext 挂载/sd-ext分区（A2SD分区）--format boot 格式化内核分区--format system 格式化系统分区--format data 格式化数据分区--format cache 格式化缓存分区--format sdcard 格式化存储卡--format sd-ext 格式化内存卡SD--mount USB storage 挂载SD卡为U盘模式-advanced 高级--Reboot Recovery 重启Recovery--Wipe Dalvik Cache 清空Dalvik缓存--Wipe Battery Stats 清空电池状态--Report Error 报告错误--Key Test 键位测试--Partition SD Card 对SD卡分区--Fix Permissions 修复权限。
安卓单词(国外英文资料)
安卓单词(国外英文资料)在当今数字化的时代，安卓操作系统已经成为全球范围内使用最广泛的移动操作系统之一。
安卓不仅为用户提供了丰富的应用和功能，还推动了移动技术的创新和发展。
然而，对于许多人来说，安卓系统中的许多专业术语和概念可能显得有些陌生和难以理解。
为了帮助用户更好地了解安卓系统，本文将介绍一些与安卓相关的常用单词和术语，并提供相关的英文资料，以便读者能够更深入地了解安卓系统的各个方面。
1. Android：安卓操作系统的名称，源自于英文单词“android”，意为“”。
2. APK：安卓应用程序的安装包文件格式，全称为“Android Package”。
3. Dalvik：安卓系统中的一个虚拟机，用于运行安卓应用程序。
4. ROM：安卓系统的固件版本，全称为“ReadOnly Memory”。
5. Root：对安卓系统进行解锁，以获得更高的权限和更广泛的控制。
6. SDK：安卓软件开发工具包，全称为“Software Development Kit”。
7. UI：用户界面，全称为“User Interface”。
8. UX：用户体验，全称为“User Experience”。
9. Widget：安卓系统中的一个小工具，可以显示在主屏幕上，提供快捷的操作和显示信息。
10. Fragment：安卓系统中的一个组件，用于实现用户界面的模块化。
1. Android Developers：安卓开发者官方网站，提供了丰富的文档、教程和资源，适合开发者学习安卓编程。
2. XDA Developers：一个安卓社区，提供了大量的安卓相关资讯、教程和讨论，适合对安卓系统感兴趣的用户。
3. Android Central：一个专注于安卓系统的新闻网站，提供了最新的安卓资讯、评测和教程。
4. Stack Overflow：一个编程问答社区，提供了大量的安卓编程问题解答，适合开发者解决安卓编程中的问题。
5. Reddit：一个社交新闻网站，有一个专门的安卓子版块，提供了大量的安卓相关讨论和分享。
Android毕设外文资料和译文
东北大学东软信息学院专业：计算机科学与技术（嵌入式软件开发方向）班级：计嵌入式000000姓名：XXXX学号：08111XXXXX指导教师：XXXX 教授2011 年12 月18 日译文这篇文档主要讲述 An droid 应用框架的核心原则。
站在高层来说，以用户为中心来设 计良好的交互程序，对于应用设计者或是开发者来说是非常重要的。
下面用例子来阐述了 activities 和tasks 的一些底层原则和机制，例如导航，多任 务，activity 重用，意图和activity栈。
这篇文档也着重讨论了一些设计决策，针对如何利用好它们去设计你的应用程序UI 。
这篇文档中的例子均是An droid 应用程序，包括默认应用程序 （比如拨号器）、Google应用程序（比如地图）。
你可以自己在 An droid 模拟器上或是 An droid 手机上去试验这些例 子。
如果你使用An droid 手机试验时，可能未提供本文档中的某些例子。
App lications, Activities, Activity Stack and Tasks理解An droid 系统中的四个基本概念对你是很有帮助的，它们分别是：App licati ons （应用）Activities（活动）Activity Stack （活动堆栈）Tasks （任务）App licati ons一个An droid 应用程序其实就是由一个或者多个Activity 组成。
它们被捆绑在一起并存放进.apk 文件中，这就是 An droid 应用程序。
An droid 中有着丰富的应用程序，比如邮 件、日历、地图定位、文本消息、联系人、照相机、打电话、音乐播放器，系统设置等应 用。
一般情况下，桌面上都会有 An droid 应用程序快捷图标，用户可以选择某一个图标来启动应用程序。
ActivitiesActivity 是An droid 应用程序的主要组成部分，activity 可以是你自己创建的，当然, 。
安卓系统翻译
Move recovery.log to SD :: Moves the recovery log file to your sdcard. (Use when you want more detailed recovery log information) 移动刷机日志文件到SD卡（需要详细的刷机数据使用）
Partition SD :: Interactive SD partitioning 自动为SD卡分区
Repair SD:ext :: Repair the ext partition 修复Ext分区
SD:ext2 to ext3 :: Convert ext2 to ext3 转换Ext2为Ext3
SD:ext3 to ext4 :: Convert ext3 to ext4 转换Ext3为Ext4 (SD 6Class以下不建议使用)
Other 其他
Fix apk uid mismatches :: Does extacly that 修复APK程序
Move apps+dalv to SD :: Moves all apps and Dalvik-cache to sdcard (This will NOT enable apps2sd!)
Nand restore :: Restore a Nand backup 还原一个备份
BART backup :: Make a BART backup (Nand + ext) BART备份（系统和Ext分区）
BART restore :: Restore latest BART backup 还原最近的BART备份
Android系统应用程序中英文对照表
htccalendarwidgetsHTC日历桌面小插件
HTCCamera照相机（没人想把它删了吧）
HtcClockWidget闹钟小插件
HtcCompressViewer
HtcContacts联系人
CertInstaller证书安装器（貌似不能删）
CheckinProvider签入服务
Clicker键盘校准（貌似是）
com.htc.FMRadioWidget桌面收音机插件（插件类都可以删，自己决定）
com.htc.FriendStreamWidget好友流小插件（可删）
com.htc.MusicWidget桌面音乐插件
HtcScreenTimeoutWidget.apk调节屏幕延时插件
HtcSettingsProvider.apk HTC设置
htcsettingwidgets.apk HTC设置小插件，WIFI、移动网络、GPS、飞行模式、蓝牙的开关（好用）
HTCSetupWizard.apk HTC安装向导
GoogleFeedback谷歌反馈（反馈啥，直接干掉）
GooglePartnerSetup Google助手（直接干掉）
GoogleQuickSearchBox谷歌搜索（删了影响到桌面的搜索插件，自启动，干掉他）
GoogleServicesFramework谷歌同步支持服务框架（删了不能同步联系人，不能登录google，我留着呢）
HtcPushMedia.apk
pk
HtcRecommendsWidget.apk
HtcRingtoneTrimmer.apk铃声剪辑（无视，删了）
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附录1：外文原文What Is Android?It can be said that, for a while, traditional desktop application developers have beenspoiled. This is not to say that traditional desktop application development is easier thanother forms of development. However, as traditional desktop application developers, wehave had the ability to create almost any kind of application we can imagine. I amincluding myself in this grouping because I got my start in desktop programming.One aspect that has made desktop programming more accessible is that we havehad the ability to interact with the desktop operating system, and thus interact with anyunderlying hardware, pretty freely (or at least with minimal exceptions). This kind offreedom to program independently, however, has never really been available to thesmall group of programmers who dared to venture into the murky waters of cell phonedevelopment.For a long time, cell phone developers comprised a small sect of a slightly larger group of developers known as embedded device developers. Seen as a less “glamorous” sibling to desktop—and later web—development, embedded device development typically got the proverbial short end of the stick as far as hardware and operating system features, because embedded device manufacturers were notoriously stingy on feature support. Embedded device manufacturers typically needed to guard their hardware secrets closely, so they gave embedded device developers few libraries to call when trying to interact with a specific device. Embedded devices differ from desktops in that an embedded device is typically a “computer on a chip.” For example, consider your standard television remote control; it is not really seen as an overwhelming achievement of technological complexity. When any button is pressed, a chip interprets the signal in a way that has been programmed into the device. This allows the device to know what to expect from the input device (key pad), and how to respond to those commands (for example, turn on the television). This is a simple form of embedded device programming. However, believe it or not, simple devices such as these are definitely related to the roots of early cell phone devices and development.Most embedded devices ran (and in some cases still run) proprietary operating systems. The reason for choosing to create a proprietary operating system rather than use any consumer system was really a product of necessity. Simple devices did not need very robust and optimized operating systems.As a product of device evolution, many of the more complex embedded devices, such as early PDAs, household security systems, and GPSs, moved to somewhat standardized operating system platforms about five years ago. Small-footprintoperating systems such as Linux, or even an embedded version of Microsoft Windows, have become more prevalent on many embedded devices. Around this time in device evolution, cell phones branched from other embedded devices onto their own path. This branching is evident when you examine their architecture.Nearly since their inception, cell phones have been fringe devices insofar as they run on proprietary software—software that is owned and controlled by the manufacturer, and is almost always considered to be a “closed” system. The practice of manufacturers using proprietary operating systems began more out of necessity than any other reason. That is, cell phone manufacturers typically used hardware that was completely developed in-house, or at least hardware that was specifically developed for the purposes of running cell phone equipment. As a result, there were no openly available, off-the-shelf software packages or solutions that would reliably interact with their hardware. Since the manufacturers also wanted to guard very closely their hardware trade secrets, some of which could be revealed by allowing access to the software level of the device, the common practice was, and in most cases still is, to use completely proprietary and closed software to run their devices. The downside to this is that anyone who wanted to develop applications for cell phones needed to have intimate knowledge of the proprietary environment within which it was to run. The solution was to purchase expensive development tools directly from the manufacturer. This isolated many of the “homebrew” develo pers.Another, more compelling “necessity” that kept cell phone development out of the hands of the everyday developer was the hardware manufacturers’ solution to the “memory versus need” dilemma. Until recently, cell phones did little more than execute and receive phone calls, track your contacts, and possibly send and receive short text messages; not really the “Swiss army knives” of technology they are today. Even as late as 2002, cell phones with cameras were not commonly found in the hands of consumers.By 1997, small applications such as calculators and games (Tetris, for example) crept their way onto cell phones, but the overwhelming function was still that of a phone dialer itself. Cell phones had not yet become the multiuse, multifunction personal tools they are today. No one yet saw the need for Internet browsing, MP3 playing, or any of the multitudes of functions we are accustomed to using today. It is possible that the cell phone manufacturers of 1997 did not fully perceive the need consumers would have for an all-in-one device. However, even if the need was present, a lack of device memory and storage capacity was an even bigger obstacle to overcome. More people may have wanted their devices to be all-in-one tools, but manufacturers still had to climb the memory hurdle.To put the problem simply, it takes memory to store and run applications on any device, cell phones included. Cell phones, as a device, until recently did not have the amount of memory available to them that would facilitate the inc lusion of “extra” programs. Within the last two years, the price of memory has reached very low levels.Device manufacturers now have the ability to include more memory at lower prices. Many cell phones now have more standard memory than the average PC had in the mid-1990s. So, now that we have the need, and the memory, we can all jump inand develop cool applications for cell phones around the world, right? Not exactly.Device manufacturers still closely guard the operating systems that run on their devices. While a few have opened up to the point where they will allow some Java-based applications to run within a small environment on the phone, many do not allow this. Even the systems that do allow some Java apps to run do not allow the kind of access to t he “core” system that standard desktop developers are accustomed to having.This barrier to application development began to crumble in November of 2007 whenGoogle, under the Open Handset Alliance, released Android. The Open Handset Allianceis a group of hardware and software developers, including Google, NTT DoCoMo,Sprint Nextel, and HTC, whose goal is to create a more open cell phone environment.The first product to be released under the alliance is the mobile device operatingsystem, Android. (For more information about the Open Handset Alliance, see)With the release of Android, Google made available a host of development toolsand tutorials to aid would-be developers onto the new system. Help files, the platformsoftware development kit (SDK), and even a developers’ community can be found atGoogle’s Android website, /android. This site should be yourstarting point, and I highly encourage you to visit the site.While cell phones running Linux, Windows, and even PalmOS are easy to find, as ofthis writing, no hardware platforms have been announced for Android to run on. HTC, LGElectronics, Motorola, and Samsung are members of the Open Handset Alliance, underwhich Android has been released, so we can only hope that they have plans for a fewAndroid-based devices in the near future. With its release in November 2007, the systemitself is still in a software-only beta. This is good news for developers because it gives usa rare advance look at a future system and a chance to begin developing applications thatwill run as soon as the hardware is released.Android, as a system, is a Java-based operating system that runs on the Linux 2.6 kernel.The system is very lightweight and full featured. Figure 1-1 shows the unmodifiedAndroid home screen.Figure 1-1 The current Android home screen as seen on the Android EmulatorAndroid applications are developed using Java and can be ported rather easily to thenew platform. If you have not yet downloaded Java or are unsure about which version youneed, I detail the installation of the development environment in Chapter 2. Other featuresof Android include an accelerated 3-D graphics engine (based on hardware support),database support powered by SQLite, and an integrated web browser.If you are familiar with Java programming or are an OOP developer of any sort, youare likely used to programmatic user interface (UI) development—that is, UI placementwhich is handled directly within the program code. Android, while recognizing and allowingfor programmatic UI development, also supports the newer, XML-based UI layout. XMLUI layout is a fairly new concept to the average desktop developer. I will cover boththe XML UI layout and the programmatic UI development in the supporting chaptersof this book.One of the more exciting and compelling features of Android is that, because of itsarchitecture, third-party applications—including those that are “home grown”—areexecuted with the same system priority as those that are bundled with the core system.This is a major departure from most systems, which give embedded system apps agreater execution priority than the thread priority available to apps created by third-partydevelopers. Also, each application is executed within its own thread using a verylightweight virtual machine.Aside from the very generous SDK and the well-formed libraries that are availabletous to develop with, the most exciting feature for Android developers is that we now haveaccess to anything the operating system has access to. In other words, if you want tocreate an application that dials the phone, you have access to the phone’s dialer; if youwant to create an application that utilizes the phone’s internal GPS (if equipped), you haveaccess to it. The potential for developers to create dynamic and intriguing applications isnow wide open.On top of all the features that are available from the Android side of the equation,Google has thrown in some very tantalizing features of its own. Developers of Androidapplications will be able to tie their applications into existing Google offerings such asGoogle Maps and the omnipresent Google Search. Suppose you want to write anapplication that pulls up a Google map of where an incoming call is emanating from,or you want to be able to store common search results with your contacts; the doors ofpossibility have been flung wide open with Android.Ask the ExpertQ: What is the difference between Google and the Open Handset Alliance?A: Google is a member of the Open Handset Alliance. Google, after purchasing the originaldeveloper of Android, released the operating system under the Open Handset Alliance.Q: Is Android capable of running any Linux software?A: Not necessarily. While I am sure that there will be ways to get around most any opensource system, applications need to be compiled using the Android SDK to run onAndroid. The main reason for this is that Android applications execute files in a specificformat; this will be discussed in later chapters.Reference：[1]Hello Android. Introdu cing Google’s Mobile Developmeng Platform 3rd.Edition,EdBurnette,The Pragmatic Bookshelf[2]The.Android.Developers.Cookbook Building Applications with the Android SDK,James Steele Nelson,Addison-Wesley[3] Pro Android Media. Developing Graphics,Music,Video and Rich Media Apps for Smartphones and Tablets,Shawn Van Every,Apress[4] Professional.Android.2.Application.Development.(Wrox,.2010,.0470565527)附录2：外文译文什么是Android?可以说，于此同时，传统的桌面应用程序开发人员已经被宠坏了。