TheIntroductionOfDesignPattern
设计模式概述DesignPatterns-NanjingUniversity
//add points, code is omitted return this.price * 0.5; } else { return this.price; } } }
计到一定额度可换取电影院赠送的奖品。
• 该系统在将来可能还要根据需要引入新的打折方式。
引言 public class MovieTicket { private double price;
//c•om不pu够te t灵he 活pri的ce 影院售票系统
public double calculate(String type) {
/i/fs(ttyupd•ee.n初etqtu始iacklse实Itgn现ore方Ca案se("student")) {
return this.price * 0.8; } //children ticket else if(type.equalsIgnoreCase("children") && this.price >= 20 ) {
引言
• 重用第三方算法库时面临的问题
• 问题
银行业务处理• 如系统何在既不修改现有接口又第不三方需算要法算库法库源代码 的基础上能够实现第三方算法库的重用是该软件
客户公端司类 开发人员必须面对的问题。
如何兼容？
加密类
DataOperation
设计模式的诞生与发展
• 模式的诞生与定义
• 模式(Pattern)起源于建筑业而非软件业 • 模式之父——美国加利佛尼亚大学环境结构中心研究所所长
设计理念及说明英语怎么说
设计理念及说明英语怎么说Design Concept and Explanation of English Terminology。
Design plays a crucial role in shaping the world around us. From the products we use to the spaces we inhabit, design influences our daily lives in countless ways. In the field of design, it is essential to have a clear understanding of the principles and concepts that guide the creative process. One such fundamental aspect is the terminology used to describe and communicate design ideas.In the context of design, terminology refers to the specific vocabulary and language used to articulate design concepts, processes, and elements. It serves as a common language that allows designers to effectively communicate their ideas and collaborate with others in the industry. Understanding and using design terminology is essential for conveying the intended message and ensuring clarity in design communication.When it comes to design terminology, the English language is widely recognized as the lingua franca of the design world. Many design concepts and principles are originally formulated and articulated in English, making it the primary language for design discourse and communication. As a result, designers around the world are expected to have a strong command of English terminology to effectively engage with the global design community.One of the key reasons for the prevalence of English in design terminology is the international reach of the design industry. Designers often collaborate with clients, colleagues, and stakeholders from diverse cultural and linguistic backgrounds. In such a globalized context, English serves as a neutral and universally understood language for discussing design concepts and ideas.Moreover, the English language has a rich and extensive vocabulary that encompasses a wide range of design terms, from basic design principles such as balance, harmony, and contrast, to specialized terms related to specific design disciplines such as graphic design, industrial design, and interior design. This comprehensive lexicon allowsdesigners to express their ideas with precision and nuance, facilitating effective communication and understanding among design professionals.In conclusion, design terminology is a fundamental aspect of the design process, and the English language serves as the primary vehicle for expressing and communicating design concepts. Designers must familiarize themselves with English design terminology to effectively engage in the global design discourse and collaborate with colleagues from diverse backgrounds. By understanding and utilizing design terminology, designers can articulate their ideas with clarity and precision, contributing to the advancement and evolution of the design industry.。
Head First Design Patterns(深入浅出设计模式)-设计模式介绍
Head First Design Patterns(深入浅出设计模式)-设计模式介绍1.Welcome to Design Patterns -设计模式介绍现在我们要住进对象村(Objectville),我们刚刚开始接触设计模式…每个人都在使用它们。
一会我们将去参加Jim和Betty的星期三晚上的模式聚会!有人已经解决了你的问题。
在这章里，你将学习到为什么(和怎么样)，你将学习到那些幸存下来的开发者的智慧和教训，他们都曾经历过类似的设计问题。
在我们做之前，我们将先看看设计模式的用途和好处，再看一些关键的面向对象设计原则，并且再通过一个实例了解模式的工作方式。
使用模式最好的方法就是把它们装入脑袋里，然后在你设计和现有的应用程序里找到你能够应用它们的地方。
相对于代码重用，使用模式你获得了经验的重用。
-1-从一个简单的模拟鸭子程序开始乔为一个制造非常成功的模拟鸭子池塘游戏(SimUDuck)的公司工作。
这个游戏可以展示很多种鸭子的游泳方式和呷呷叫声。
系统最初的设计者们使用了标准的面向对象技术，他们创建了一个Duck基类供所有其它类型的鸭子继承。
去年，竞争者们给公司带来了越来越多的压力。
经过历时一周在高尔夫球赛场上的集体讨论，公司的经理们都觉得该是进行一次大改革的时候了。
他们需要在下周在毛伊岛举行的股东大会上展示一些真正给人深刻印象的东西。
-2-但是我们现在需要鸭子可以飞经理们确定会飞的鸭子就是模拟器需要的用来击败其他竞争者的东西。
当然，乔的经理告诉他们，对于乔来说在一周内迅速搞定这些根本不是问题。
“毕竟”，乔的上司说，“他是一个面向对象的程序员…那些有什么难的呢？”乔想：我仅仅只需要在Duck类里增加fly()方法，然后所有其他鸭子就都可以继承它了。
现在是展示我真正的面向对象才华的时候了。
-3-但是有些事情严重错误了…乔的上司：乔，我正在股东大会上。
他们刚看完演示，很多橡皮鸭子在屏幕上四处乱飞。
这是你在开玩笑吗？…发生了什么事？乔没有注意到并不是所有Duck的子类都需要fly()方法。
lecture-11-pattern-1
SoftwareArchitecture and Design Pattern
22
SoftwareArchitecture & Design Pattern
Graphics features under varios O/S
SoftwareArchitecture and Design Pattern
SoftwareArchitecture and Design Pattern
6
SoftwareArchitecture & Design Pattern
Design Pattern Types
• Creational Pattern - deal with initializing/configuring objects
SoftwareArchitecture & Design Pattern
Pattern Scope --- what the pattern applies to
• Class Patterns - focus on the relationships between classes and their subclasses - involve inheritance reuse • Object Patterns - focus on the relationships between objects - involve composition reuse
SoftwareArchitecture and Design Pattern
2
SoftwareArchitecture & Design Pattern
SoftwareArchitecture and Design Pattern
设计专业介绍英语作文模板
设计专业介绍英语作文模板英文回答：Program Introduction for Design Major。
Design is a field of study that focuses on the creation of visual and functional objects. Designers use a varietyof techniques and materials to create products that areboth aesthetically pleasing and useful.The Design major at [University Name] provides students with a comprehensive foundation in the principles of design. Students will learn about the history of design, thedifferent elements of design, and the process of design. They will also develop skills in drawing, sketching, 3D modeling, and other design software.Graduates of the Design major will be prepared for a variety of careers in the design field. They will be ableto work as graphic designers, web designers, industrialdesigners, and more. They will also be able to start their own businesses or work as freelance designers.The Design major at [University Name] is a great choice for students who are interested in a career in the design field. The program provides students with the skills and knowledge they need to succeed in this competitive industry.中文回答：设计专业简介。
介绍设计的英语作文_专业高分英语作文2篇
介绍设计的英语作文_专业高分英语作文2篇关于”介绍设计“的英语作文模板2篇，作文题目：Introduction design。
以下是关于介绍设计的专业英语模板，每篇作文均为高分模板带翻译。
高分英语作文1：Introduction design中文翻译：景观是指土地和土地中的空间和物体的综合体，它是地球上一个复杂的自然过程和人类活动的一个品牌。
景观设计的要素包括自然景观要素和人工景观要素，自然景观要素主要指自然景观，如山丘、山丘、山丘等古树、石头、河流、湖泊、海洋等人工景观的主要元素是文物、文物古迹、园林绿化、艺术小品、交易会、建筑建筑、广场等这些景观元素为创造高品质的城市空间环境提供了大量素材，但要形成独特的城市景观，必须系统地组织各种景观要素，形成完整和谐的景观系统和有序的空间形态。
万能作文模板2：中文翻译：卢浮宫金字塔是法国巴黎卢浮宫博物馆（m useée du Louvre）庭院中的一个大型玻璃和金属金字塔，周围环绕着三个较小的金字塔。
大金字塔作为博物馆的主要入口，建成后已成为巴黎市的地标性建筑“实心为死者，透明为生者”贝聿铭。
满分英语范文3：介绍设计Reduce all the pain, stress and tension our place is very clean, very, beautiful and personal refresh all the best placesin your life rela某 shower we accept credit card beautiful asian meur with soft hands and gentle touch deep tissue, finger pressure, Swiss mage, super clean place, very quiet, e某perienced, skilled 2 or 4 hands Beautiful girl, best service. We accept credit cards.中文翻译：减少所有的疼痛，压力和紧张感我们的地方非常干净，非常，美丽和私人的刷新你的生活全部最好的地方放松淋浴我们接受信用卡漂亮的亚洲师用柔软的手和温柔的触感深层组织，指压，瑞典，超级干净的地方，非常安静，经验丰富，技术娴熟2或4手，漂亮女孩最好的服务最好我们接受信用卡。
design patterns
Design Patterns: Elements of Reusable Object-OrientedSoftwareAuthor(s)The "Gang of Four":Erich Gamma,Richard Helm,Ralph Johnson,John VlissidesCountry USASubject(s)Design patterns, softwareengineering, object-orientedprogrammingPublisher Addison-WesleyPublicationdate1994Pages395ISBN0-201-63361-2OCLC Number 31171684(/oclc/31171684)DeweyDecimal005.1/2 20LC Classification QA76.64 .D47 1995Design PatternsFrom Wikipedia, the free encyclopedia(Redirected from Design Patterns (book)) Design Patterns: Elements of Reusable Object-Oriented Software is a software engineering book describing recurring solutions to common problems in software design. The book's authors are Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides with a foreword by Grady Booch. The authors are often referred to as the Gang of Four, GoF,[1]or Go4. The book is divided into two parts, with the first two chapters exploring the capabilities and pitfalls of object-oriented programming, and the remaining chapters describing 23 classic software design patterns. The book includes examples in C++and Smalltalk.The original publication date of the book was October 21, 1994 with a 1995 copyright, and as of March 2011, the book was in its 39th printing. The book was first made available to the public at OOPSLA meeting held in Portland, Oregon, in October 1994. It has been highly influential to the field of software engineering and is regarded as an important source for object-oriented design theory and practice. More than 500,000 copies have been sold in English and in 13 other languages. Contents■1Introduction, Chapter 1■2Case study, Chapter 2■2.1Document Structure■2.2Formatting■2.3Embellishing the UserInterface■2.4Supporting Multiple Look-And-Feel Standards■2.5Supporting Multiple WindowSystems■2.6User Operations■2.7Spell Check and Hyphenation ■3Patterns by Type■3.1Creational■3.2Structural■3.3Behavioral■4See also■5External Links■6ReferencesIntroduction, Chapter 1Chapter 1 is a discussion of object-oriented design techniques, based on the authors' experience, which they believe would lead to good object-oriented software design, including:■"Program to an 'interface', not an 'implementation'." (Gang of Four 1995:18)■"Favor 'object composition' over 'class inheritance'." (Gang of Four 1995:20)The authors claim the following as advantages of interfaces over implementation:■clients remain unaware of the specific types of objects they use, as long as the object adheres to the interface■clients remain unaware of the classes that implement these objects; clients only know about the abstract class(es) defining the interfaceUse of an interface also leads to dynamic binding and polymorphism, which is consequentially important to object-oriented programming.The authors refer to inheritance as white-box reuse, with white-box referring to visibility, because the internals of parent classes are often visible to subclasses. In contrast, the authors refer to object composition(in which objects with well-defined interfaces are used dynamically at runtime by objects obtaining references to other objects) as black-box reuse because no internal details of composed objects need be visible in the code using them.The authors discuss the tension between inheritance and encapsulation at length and state that in their experience, designers overuse inheritance (Gang of Four 1995:20). The danger is stated as follows:"Because inheritance exposes a subclass to details of its parent's implementation, it's often said that 'inheritance breaks encapsulation'". (Gang of Four 1995:19)They warn that the implementation of a subclass can become so bound up with the implementation of its parent class that any change in the parent's implementation will force the subclass to change. Furthermore, they claim that a way to avoid this is to inherit only from abstract classes—but then, they point out that there is minimal code reuse.Using inheritance is recommended mainly when adding to the functionality of existing components, reusing most of the old code and adding relatively small amounts of new code.To the authors, 'delegation' is an extreme form of object composition that can always be used to replace inheritance. Delegation involves two objects: a 'sender' passes itself to a 'delegate' to let the delegate refer to the sender. Thus the link between two parts of a system are established only at runtime, not at compile-time. The Callback article has more information about delegation.The authors also discuss so-called parameterized types, which are also known as generics(Ada, Eiffel, Java, C#, , and Delphi) or templates (C++). These allow any type to be defined without specifying all the other types it uses—the unspecified types are supplied as 'parameters' at the point of use.The authors admit that delegation and parameterization are very powerful but add a warning: "Dynamic, highly parameterized software is harder to understand and build than more static software." (Gang of Four 1995:21)The authors further distinguish between 'Aggregation', where one object 'has' or 'is part of' another object (implying that an aggregate object and its owner have identical lifetimes) and acquaintance, where one object merely 'knows of' another object. Sometimes acquaintance is called 'association' or the 'using' relationship. Acquaintance objects may request operations of each other, but they aren't responsible for each other. Acquaintance is a weaker relationship than aggregation and suggests much looser coupling between objects, which can often be desirable for maximum maintainability in a design.The authors employ the term 'toolkit' where others might today use 'class library', as in C# or Java. In their parlance, toolkits are the object-oriented equivalent of subroutine libraries, whereas a'framework' is a set of cooperating classes that make up a reusable design for a specific class of software. They state that applications are hard to design, toolkits are harder, and frameworks are the hardest to design.Case study, Chapter 2Chapter 2 is a step-by-step case study on "the design of a 'What-You-See-Is-What-You-Get' (or'WYSIWYG') document editor called Lexi." (pp33)The chapter goes through seven problems that must be addressed in order to properly design Lexi, including any constraints that must be followed. Each problem is analyzed in depth, and solutions are proposed. Each solution is explained in full, including pseudo-code and a slightly modified version of Object Modeling Technique where appropriate.Finally, each solution is associated directly with one or more design patterns. It is shown how the solution is a direct implementation of that design pattern.The seven problems (including their constraints) and their solutions (including the pattern(s) referenced), are as follows:Document StructureThe document is "an arrangement of basic graphical elements" such as characters, lines, other shapes, etc., that "capture the total information content of the document"(pp35). The structure of the document contains a collection of these elements, and each element can in turn be a substructure of other elements.Problems and Constraints1.Text and graphics should be treated the same way (that is, graphics aren't a derived instance oftext, nor vice versa)2.The implementation should treat complex and simple structures the same way. It should nothave to know the difference between the two.3.Specific derivatives of abstract elements should have specialized analytical elements. Solution and PatternA recursive composition is a hierarchical structure of elements, that builds "increasingly complex elements out of simpler ones" (pp36). Each node in the structure knows of its own children and its parent. If an operation is to be performed on the whole structure, each node calls the operation on its children (recursively).This is an implementation of the composite pattern, which is a collection of nodes. The node is an abstract base class, and derivatives can either be leaves (singular), or collections of other nodes (which in turn can contain leaves or collection-nodes). When an operation is performed on the parent, that operation is recursively passed down the hierarchy.FormattingFormatting differs from structure. Formatting is a method of constructing a particular instance of the document's physical structure. This includes breaking text into lines, using hyphens, adjusting for margin widths, etc.Problems and Constraints1.Balance between (formatting) quality, speed and storage space2.Keep formatting independent (uncoupled) from the document structure.Solution and PatternA Compositor class will encapsulate the algorithm used to format a composition. Compositor is a subclass of the primitive object of the document's structure. A Compositor has an associated instance of a Composition object. When a Compositor runs its Compose(), it iterates through each element of its associated Composition, and rearranges the structure by inserting Row and Column objects as needed.The Compositor itself is an abstract class, allowing for derivative classes to use different formatting algorithms (such as double-spacing, wider margins, etc.)The Strategy Pattern is used to accomplish this goal. A Strategy is a method of encapsulating multiple algorithms to be used based on a changing context. In this case, formatting should be different, depending on whether text, graphics, simple elements, etc., are being formatted.Embellishing the User InterfaceThe ability to change the graphical interface that the user uses to interact with the document.Problems and Constraints1.Demarcate a page of text with a border around the editing area2.Scroll bars that let the user view different parts of the pageer interface objects should not know about the embellishments4.Avoid an "explosion of classes" that would be caused by subclassing for "every possiblecombination of embellishments" and elements (p44)Solution and PatternThe use of a transparent enclosure allows elements that augment the behaviour of composition to be added to a composition. These elements, such as Border and Scroller, are special subclasses of the singular element itself. This allows the composition to be augmented, effectively adding state-like elements. Since these augmentations are part of the structure, their appropriate Operation()will be called when the structure's Operation()is called. This means that the client does not need any special knowledge or interface with the structure in order to use the embellishments.This is a Decorator pattern, one that adds responsibilities to an object without modifying the object itself.Supporting Multiple Look-And-Feel StandardsLook-and-feel refers to platform-specific UI standards. These standards "define guidelines for how applications appear and react to the user" (pp47).Problems and Constraints1.The editor must implement standards of multiple platforms so that it is portable2.Easily adapt to new and emergent standards3.Allow for run-time changing of look-and-feel (i.e.: No hard-coding)4.Have a set of abstract elemental subclasses for each category of elements (ScrollBar, Buttons,etc.)5.Have a set of concrete subclasses for each abstract subclass that can have a different look-and-feel standard. (ScrollBar having MotifScrollBar and PresentationScrollBar for Motif andPresentation look-and-feels)Solution and PatternSince object creation of different concrete objects cannot be done at runtime, the object creation process must be abstracted. This is done with an abstract guiFactory, which takes on the responsibility of creating UI elements. The abstract guiFactory has concrete implementations, such as MotifFactory, which creates concrete elements of the appropriate type (MotifScrollBar). In this way, the program need only ask for a ScrollBar and, at run-time, it will be given the correct concrete element.This is an Abstract Factory. A regular factory creates concrete objects of one type. An abstract factory creates concrete objects of varying types, depending on the concrete implementation of the factory itself. Its ability to focus on not just concrete objects, but entire families of concrete objects "distinguishes it from other creational patterns, which involve only one kind of product object" (pp51).Supporting Multiple Window SystemsJust as look-and-feel is different across platforms, so is the method of handling windows. Each platform displays, lays out, handles input to and output from, and layers windows differently. Problems and Constraints1.The document editor must run on many of the "important and largely incompatible windowsystems" that exist (p. 52)2.An Abstract Factory cannot be used. Due to differing standards, there will not be a commonabstract class for each type of widget.3.Do not create a new, nonstandard windowing systemSolution and PatternIt is possible to develop "our own abstract and concrete product classes", because "all window systems do generally the same thing" (p. 52). Each window system provides operations for drawing primitive shapes, iconifying/de-iconifying, resizing, and refreshing window contents.An abstract base Window class can be derived to the different types of existing windows, such as application, iconified, dialog. These classes will contain operations that are associated with windows, such as reshaping, graphically refreshing, etc. Each window contains elements, whose Draw() functions are called upon by the Window's own draw-related functions.In order to avoid having to create platform-specific Window subclasses for every possible platform, an interface will be used. The Window class will implement a Window implementation (WindowImp) abstract class. This class will then in turn be derived into multiple platform-specific implementations, each with platform-specific operations. Hence, only one set of Window classes are needed for each type of Window, and only one set of WindowImp classes are needed for each platform (rather than the Cartesian product of all available types and platforms). In addition, adding a new window type does not require any modification of platform implementation, or vice-versa.This is a Bridge pattern. Window and WindowImp are different, but related. Window deals with windowing in the program, and WindowImp deals with windowing on a platform. One of them can change without ever having to modify the other. The Bridge pattern allows these two "separate class hierarchies to work together even as they evolve independently" (p. 54).User OperationsAll actions the user can take with the document, ranging from entering text, changing formatting, quitting, saving, etc.Problems and Constraints1.Operations must be accessed through different inputs, such as a menu option and a keyboardshortcut for the same command2.Each option has an interface, which should be modifiable3.Operations are implemented in several different classes4.In order to avoid coupling, there must not be a lot of dependencies between implementationand user interface classes.5.Undo and redo commands must be supported on most document changing operations, with noarbitrary limit on the number of levels of undo6.Functions are not viable, since they don't undo/redo easily, are not easily associated with astate, and are hard to extend or reuse.7.Menus should be treated like hierarchical composite structures. Hence, a menu is a menu itemthat contains menu items which may contain other menu items, etc.Solution and PatternEach menu item, rather than being instantiated with a list of parameters, is instead done with a Command object.Command is an abstract object that only has a single abstract Execute()method. Derivative objects extend the Execute()method appropriately (i.e., the PasteCommand.Execute()would utilize the content's clipboard buffer). These objects can be used by widgets or buttons just as easily as they can be used by menu items.To support undo and redo, Command is also given Unexecute()and Reversible(). In derivative classes, the former contains code that will undo that command, and the latter returns a boolean value that defines if the command is undoable. Reversible()allows some commands to be non-undoable, such as a Save command.All executed Commands are kept in a list with a method of keeping a "present" marker directly after the most recently executed command. A request to undo will call the Command.Unexecute()directly before "present", then move "present" back one command. Conversely, a Redo request will call Command.Execute()after "present", and move "present" forward one.This Command approach is an implementation of the Command pattern. It encapsulates requests in objects, and uses a common interface to access those requests. Thus, the client can handle different requests, and commands can be scattered throughout the application.Spell Check and HyphenationThis is the document editor's ability to textually analyze the contents of a document. Although there are many analyses that can be performed, spell check and hyphenation-formatting are the focus. Problems and Constraints1.Allow for multiple ways to check spelling and identify places for hyphenation2.Allow for expansion for future analysis (e.g., word count, grammar check)3.Be able to iterate through a text's contents without access to the text's actual structure (e.g.,array, linked list, string)4.Allow for any manner of traversal of document (beginning to end, end to beginning,alphabetical order, etc.)Solution and PatternRemoving the integer-based index from the basic element allows for a different iteration interface to be implemented. This will require extra methods for traversal and object retrieval. These methods are put into an abstract Iterator interface. Each element then implements a derivation of the Iterator, depending on how that element keeps its list (ArrayIterator, LinkListIterator, etc.). Functions for traversal and retrieval are put into the abstract Iterator interface. Future Iterators can be derived based on the type of list they will be iterating through, such as Arrays or Linked Lists. Thus, no matter what type of indexing method any implementation of the element uses, it will have the appropriate Iterator.This is an implementation of the Iterator pattern. It allows the client to traverse through any object collection, without needing to access the contents of the collection directly, or be concerned about the type of list the collection's structure uses.Now that traversal has been handled, it is possible to analyze the elements of a structure. It is not feasible to build each type of analysis into the element structure themselves; every element would need to be coded, and much of the code would be the same for similar elements.Instead, a generic CheckMe()method is built into the element's abstract class. Each Iterator is given a reference to a specific algorithm (such as spell check, grammar check, etc.). When that Iterator iterates through its collection, it calls each element's CheckMe, passing the specified algorithm. CheckMe then passes a reference to its element back to said algorithm for analysis.Thus, to perform a spell check, a front-to-end iterator would be given a reference to a SpellCheck object. The iterator would then access each element, executing its CheckMe()method with the SpellCheck parameter. Each CheckMe would then call the SpellCheck, passing a reference to the appropriate element.In this manner, any algorithm can be used with any traversal method, without hard-code coupling one with the other. For example, Find can be used as "find next" or "find previous", depending on if a "forward" iterator was used, or a "backwards" iterator.In addition, the algorithm themselves can be responsible for dealing with different elements. For example, a SpellCheck algorithm would ignore a Graphic element, rather than having to program every Graphic-derived element to not send themselves to a SpellCheck.Patterns by TypeCreationalCreational patterns are ones that create objects for you, rather than having you instantiate objects directly. This gives your program more flexibility in deciding which objects need to be created for a given case.■Abstract Factory groups object factories that have a common theme.■Builder constructs complex objects by separating construction and representation.■Factory Method creates objects without specifying the exact class to create.■Prototype creates objects by cloning an existing object.■Singleton restricts object creation for a class to only one instance.StructuralThese concern class and object composition. They use inheritance to compose interfaces and define ways to compose objects to obtain new functionality.■Adapter allows classes with incompatible interfaces to work together by wrapping its own interface around that of an already existing class.■Bridge decouples an abstraction from its implementation so that the two can vary independently.■Composite composes zero-or-more similar objects so that they can be manipulated as one object.■Decorator dynamically adds/overrides behaviour in an existing method of an object.■Facade provides a simplified interface to a large body of code.■Flyweight reduces the cost of creating and manipulating a large number of similar objects.■Proxy provides a placeholder for another object to control access, reduce cost, and reduce complexity.BehavioralMost of these design patterns are specifically concerned with communication between objects.■Chain of responsibility delegates commands to a chain of processing objects.■Command creates objects which encapsulate actions and parameters.■Interpreter implements a specialized language.■Iterator accesses the elements of an object sequentially without exposing its underlying representation.■Mediator allows loose coupling between classes by being the only class that has detailed knowledge of their methods.■Memento provides the ability to restore an object to its previous state (undo).■Observer is a publish/subscribe pattern which allows a number of observer objects to see an event.■State allows an object to alter its behavior when its internal state changes.■Strategy allows one of a family of algorithms to be selected on-the-fly at runtime.■Template method defines the skeleton of an algorithm as an abstract class, allowing its subclasses to provide concrete behavior.■Visitor separates an algorithm from an object structure by moving the hierarchy of methods into one object.See also■Design pattern (computer science)■Enterprise Integration Patterns■GRASP (object-oriented design)■Pedagogical patternsExternal Links■GoF Design Patterns with examples using Java and UML2(/biblioteca/gof-design-patterns/)a quick-guide book to the basic GoF design patterns (pdf)References1.^Gang Of Four(http://c/cgi/wiki?GangOfFour), Content Creation Wiki for People Projects AndPatterns in Software Development.Retrieved from "/w/index.php?title=Design_Patterns&oldid=551041406" Categories: Software design patterns Software engineering books1994 booksAddison-Wesley books■This page was last modified on 21 April 2013 at 08:34.■Text is available under the Creative Commons Attribution-ShareAlike License;additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy.Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.。
设计理念及说明英文版
设计理念及说明英文版Design Concept and ExplanationDesigning is not just about creating aesthetically pleasing objects, but also about solving problems and improving user experiences. As a designer, my ultimate goal is to create designs that are both functional and visually appealing.I believe that good design should be user-centered. It should consider the needs, preferences, and limitations of the users. By putting myself in the shoes of the users and understanding their perspectives, I can create designs that truly meet their needs and desires.In order to achieve this, I employ a user research and empathy-driven approach. This involves conducting thorough research on the target audience, including their demographics, preferences, behaviors, and needs. By understanding the users' context, I can design products or services that are tailored to their specific requirements.Another important aspect of my design philosophy is simplicity. I strive to create designs that are intuitive and easy to use. A cluttered and complex design can confuse and frustrate users. By simplifying the design and minimizing unnecessary elements, I can enhance the user experience and improve usability. Additionally, I believe that sustainability should be an integral part of design. In a world facing environmental challenges, it is important to consider the environmental impact of the products andservices we design. I focus on creating designs that are environmentally friendly, using materials and manufacturing processes that minimize waste and reduce carbon footprint.Furthermore, I believe that collaboration is essential in the design process. By working closely with clients, stakeholders, and other members of the design team, I can gather different perspectives and insights, leading to better and more innovative designs. Collaboration also allows me to learn from others and continuously improve my skills.Lastly, I strive to incorporate creativity and innovation into my designs. I believe that design should push boundaries and challenge traditional norms. By thinking outside the box and exploring new possibilities, I can create designs that are unique, fresh, and exciting.In conclusion, my design philosophy revolves around user-centered design, simplicity, sustainability, collaboration, and creativity. By focusing on these principles, I aim to create designs that not only solve problems but also enhance the lives of the users and make a positive impact on the world.。
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缺点： 缺点：
不易于添加新产品的类型。 不易于添加新产品的类型。
Structure Pattern
Adapter Proxy
Adapter(适配器模式) Adapter(适配器模式)
将一个类的接口转化成客户希望的另一个接口。 将一个类的接口转化成客户希望的另一个接口。 Adapter接口使得原本由于接口不兼容而不能一起 Adapter接口使得原本由于接口不兼容而不能一起 工作的那些类可以一起工作。 工作的那些类可以一起工作。
Behavior Pattern
Iterator interpreter
Iterator(迭代器) Iterator(迭代器) 迭代器
提供一种方法顺序访问一个聚合对象中各个元素， 提供一种方法顺序访问一个聚合对象中各个元素， 而又不暴露对象的内部表示。 而又不暴露对象的内部表示。 迭 代 器 模 式 结 构 图
• 提供一个接口，让该接口负责创建一系列相关 提供一个接口， 或者相互依赖的对象，无需指定它们具体的类。 或者相互依赖的对象，无需指定它们具体的类。 抽象工厂模式结构图
பைடு நூலகம்
优点： 优点：
•易于交换产品系列； 易于交换产品系列； 易于交换产品系列 •让具体的创建实例过程与客户端分离，客户端通过其抽象接 让具体的创建实例过程与客户端分离， 让具体的创建实例过程与客户端分离 口操纵实例，产品的具体类名也被具体工厂的实现分离， 口操纵实例，产品的具体类名也被具体工厂的实现分离，不 会出现在客户代码中。 会出现在客户代码中。
谢谢！ 谢谢！
Interpreter(解释器模式) Interpreter(解释器模式)
解释器模式（Interpreter），给定一个语言， 解释器模式（Interpreter），给定一个语言，定义一种文法 ），给定一个语言 的表示，并定义一个解释器， 的表示，并定义一个解释器，这个解释器使用该表示来解释 语言中的句子。 语言中的句子。
系统的数据和行为都正确，但接口不符时，考虑使用适配器， 系统的数据和行为都正确，但接口不符时，考虑使用适配器，目的是使 控制范围外的一个原有对象与谋而接口匹配。 控制范围外的一个原有对象与谋而接口匹配。适配器模式主要应用于希 望复用一些存在的类，但是接口又与复用环境要求不一致的情况。 望复用一些存在的类，但是接口又与复用环境要求不一致的情况。
The Introduction of Design Pattern
Design Pattern
• Creational Pattern • Structural Pattern • Behavior Pattern
Creational Pattern
Abstract Factory
Factory(抽象工厂模式 抽象工厂模式) Abstract Factory(抽象工厂模式)
适 配 器 模 式 结 构 图
Proxy(代理模式) Proxy(代理模式)
为其他对象提供一种代理以控制对这个对象 的访问。 的访问。
代理模式结构图
应用： 应用：
1.远程代理，也就是为一个对象在不同的地址空间提供局部代表。 1.远程代理，也就是为一个对象在不同的地址空间提供局部代表。这样 远程代理 可以隐藏一个对象存在于不同地址空间的事实； 可以隐藏一个对象存在于不同地址空间的事实； 2.虚拟代理，是根据需要创建开销很大的对象。通过它来存放实例化需 2.虚拟代理，是根据需要创建开销很大的对象。 虚拟代理 要很长时间的真实对象； 要很长时间的真实对象； 3.安全代理 用来控制真实对象访问时的权限； 安全代理， 3.安全代理，用来控制真实对象访问时的权限； 4.智能指引 是指当调用真实对象时，代理处理另外一些事。 智能指引， 4.智能指引，是指当调用真实对象时，代理处理另外一些事。
解 释 器 模 式 结 构 图
解释器模式需要解决的是，如果一种特定类型的问 如果一种特定类型的问 题发生的频率足够高， 题发生的频率足够高，那么可能就值得将该问题的 各个实例表述为一个简单语言中的句子。 各个实例表述为一个简单语言中的句子。这样就可 以构建一个解释器， 以构建一个解释器，该解释器通过解释这些句子来 解决问题。 解决问题。