delphi中dll综合运用的例子

delphi中dll综合运用的例子(动态加载插件)2008年01月15日星期二 10:591,新建dll客户端模块---------------dll工程文件PlugIns.dll------------------------------- library PlugIns;{ Important note about DLL memory management: ShareMem must be the first unit in your library's USES clause AND your project's (select Project-View Source) USES clause if your DLL exports any procedures or functions that pass strings as parameters or function results. This applies to all strings passed to and from your DLL--even those that are nested in records and classes. ShareMem is the interface unit to the BORLNDMM.DLL shared memory manager, which must be deployed along with your DLL. To avoid using BORLNDMM.DLL, pass string information using PChar or ShortString parameters. }usesSysUtils,Classes,PlugInFrm in 'PlugInFrm.pas' {FrmPlugIns};{$R *.res}//输出接口函数exportsShowDLLForm,GetCaption;beginend.-------------新建模块PlugInFrm.pas的窗体文件---------------unit PlugInFrm;interfaceusesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls;typeTFrmPlugIns = class(TForm)Label1: TLabel;private{ Private declarations }public{ Public declarations }end;//定义ShowDLLForm,用于打开本窗体function ShowDLLForm(AHandle: THandle; ACaption: string): Boolean; Stdcall;//输出标题function GetCaption: Pchar; stdcall;implementation{$R *.dfm}//输出标题function GetCaption: Pchar; stdcall;beginResult := '插件演示NO1';end;//打开本窗体function ShowDLLForm(AHandle: THandle; ACaption: string): Boolean; varDLL_Form: TfrmPlugins;beginresult := true;tryapplication.Handle := AHandle; //传递应用程序地址DLL_Form := TFrmPlugins.Create(Application);//创建窗体tryDLL_Form.caption := Acaption;//给窗体标题赋值DLL_Form.ShowModal; //模式显示窗体finallyDLL_Form.Free;end;exceptresult := false;end;end;end.2,新建工程主模块-------------------新建主窗体文件MainFrm.pas--------------unit MainFrm;interfaceusesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, Menus;typeTFrmMain = class(TForm)MainMenu1: TMainMenu;N1: TMenuItem;N2: TMenuItem;N_Plugins: TMenuItem;procedure FormCreate(Sender: TObject);procedure FormDestroy(Sender: TObject);private{ Private declarations }FForm: TForm;procedure LoadPlugIns; //初始化插件，也就装载插件，并在菜单提供调用procedure PlugInsClick(Sender: TObject); //插件菜单点击事件procedure FreePlugIns; //释放插件public{ Public declarations }end;varFrmMain: TFrmMain;implementation{$R *.dfm}type//定义接口函数类型TShowDLLForm = function(AHandle: THandle; ACaption: string): Boolean; Stdcall;TGetCaption = function: Pchar; StdCall;EDLLLoadError = class(Exception);//定义TTestPlugIn类，存放caption,Address,call等信息TTestPlugIn = classCaption: string;//存取加载后，GetCaption返回的标题Address: THandle; //存取加载DLL的句柄Call: Pointer; //存取ShowDLLForm函数句柄end;varShowDllForm: TShowDllForm; //声明接口函数类型Plugins: TList; //存放每一个DLL加载后的相关信息StopSearch: Boolean;//查找文件，并存于Files中procedure SearchFileExt(const Dir, Ext: string; Files: TStrings);varFound: TSearchRec;Sub: string;i: Integer;Dirs: TStrings;Finished: Integer;beginStopSearch := False;Dirs := TStringList.Create;Finished := FindFirst(Dir + '*.*', 63, Found);while (Finished = 0) and not (StopSearch) dobeginif ([1] <> '.') thenbeginif (Found.Attr and faDirectory = faDirectory) thenDirs.Add(Dir + ) //Add to the directories list.elseif Pos(UpperCase(Ext), UpperCase()) > 0 thenFiles.Add(Dir + );end;Finished := FindNext(Found);end;FindClose(Found);if not StopSearch thenfor i := 0 to Dirs.Count - 1 doSearchFileExt(Dirs[i], Ext, Files);Dirs.Free;end;//初始化插件，也就装载插件，并在菜单提供调用procedure TfrmMain.LoadPlugIns;varFiles: TStrings;i: Integer;TestPlugIn: TTestPlugIn;NewMenu: TMenuItem;GetCaption: TGetCaption;beginFiles := TStringList.Create;Plugins := TList.Create;//查找指定目录下的.dll文件，并存于Files对象中SearchFileExt(ExtractFilepath(Application.Exename), '.dll', Files); //加载查找到的DLLfor i := 0 to Files.Count - 1 dobeginTestPlugIn := TTestPlugIn.Create;TestPlugIn.Address := LoadLibrary(PChar(Files[i]));if TestPlugIn.Address = 0 thenraise EDLLLoadError.Create('装载' + PChar(Files[i]) + '失败');try@GetCaption := GetProcAddress(TestPlugIn.Address,'GetCaption');TestPlugIn.Caption := GetCaption;TestPlugIn.Call := GetProcAddress(TestPlugIn.Address,'ShowDLLForm');PlugIns.Add(TestPlugIn);//创建菜单，并将菜单标题，Onclick事件赋值NewMenu := TMenuItem.Create(Self);NewMenu.Caption := TestPlugIn.Caption;NewMenu.OnClick := PlugInsClick;NewMenu.Tag := i;N_plugins.Add(NewMenu); //每次在菜单下新增一个模块菜单 exceptraise EDLLLoadError.Create('初始化失败');end;end;Files.Free;end;//插件菜单点击事件procedure TfrmMain.PlugInsClick(Sender: TObject);begin//根据菜单的tag属性对应函数调用的地址@showDllForm := TTestPlugIn(PlugIns[TMenuItem(Sender).Tag]).Call;//执行showDllForm函数if not showDllForm(application.Handle,TTestPlugIn(PlugIns[TMenuItem(Sender).Tag]).caption) then showmessage('打开窗体错误');end;//释放插件procedure TfrmMain.FreePlugIns;vari: Integer;begin//将加载的插件全部释放for i := 0 to PlugIns.Count - 1 dobeginFreeLibrary(TTestPlugIn(PlugIns[i]).Address);end;//释放plugIns对象PlugIns.Free;end;procedure TfrmMain.FormCreate(Sender: TObject);beginLoadPlugIns;end;procedure TfrmMain.FormDestroy(Sender: TObject);beginFreePlugins;end;end.-------------------------end-----------------------类别：Delphi | | 添加到搜藏 | 分享到i贴吧 | 浏览(1342) | 评论(2)上一篇：统计每天数据的变化量下一篇：基于Delphi的融合DLL中的窗口最近读者：登录后，您就出现在这里。