文章摘要： 编写软件时常常使用到DLL文件，本文就使用DLL文件中封装的窗口来说说Delphi中在DLL如何封装窗口，如何调用DLL中封装的窗口，及MDI-Child在DLL中载入并使用
一、在DLL中封装窗口 打开Delphi新建一个DLL工程，保存为usedll，生成代码
| library usedll; { Important note about DLL memory management: ShareMem must be thefirst unit in your library's USES clause AND your project's (selectProject-View Source) USES clause if your DLL exports any procedures orfunctions that pass strings as parameters or function results. Thisapplies to all strings passed to and from your DLL--even those thatare nested in records and classes. ShareMem is the interface unit tothe BORLNDMM.DLL shared memory manager, which must be deployed alongwith your DLL. To avoid using BORLNDMM.DLL, pass string informationusing PChar or ShortString parameters. } usesSysUtils,Classes; {$R *.res} beginend. |
新建一个窗体，添加一个Label和Button，设置如下：
| object Form1: TForm1Left = 192Top = 133Width = 334Height = 221Caption = 'DLL'#20013#20351#29992#31383#20307Color = clBtnFaceFont.Charset = DEFAULT_CHARSETFont.Color = clWindowTextFont.Height = -11Font.Name = 'MS Sans Serif'Font.Style = []OldCreateOrder = FalsePixelsPerInch = 96TextHeight = 13object Label1: TLabelLeft = 104Top = 80Width = 80Height = 13Caption = 'DLL'#20013#20351#29992#31383#20307endobject Button1: TButtonLeft = 120Top = 152Width = 75Height = 25Caption = #30830#23450TabOrder = 0OnClick = Button1Clickendend |
添加一过程：procedure LoadForm; export;procedure LoadForm;beginForm1 := TForm1.Create(Application);tryForm1.ShowModal;finallyForm1.Free;end;end;
全部完整的代码：
| library usedll; usesSysUtils,Classes,Form_Unit in 'Form_Unit.pas' {Form1}; {$R *.res}exportsLoadForm index 1;begin end. |
| unit Form_Unit; interface usesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls; typeTForm1 = class(TForm)Label1: TLabel;Button1: TButton;procedure Button1Click(Sender: TObject);private{ Private declarations }public{ Public declarations }end; varForm1: TForm1;ApplicationName: String;procedure LoadForm(Handle: THandle; AppName: ShortString); export; implementation {$R *.dfm}procedure LoadForm(Handle: THandle; AppName: ShortString);beginApplication.Handle := Handle;ApplicationName := AppName;Form1 := TForm1.Create(Application);tryForm1.ShowModal;finallyForm1.Free;end;end; procedure TForm1.Button1Click(Sender: TObject);beginself.close;end; end. |
编译后生成usedll.dll文件，至此DLL文件就完成了
二、调用DLL中封装的窗口
新建一个工程，添加一个Button，窗体布局如下：
| object Form1: TForm1Left = 192Top = 133Width = 336Height = 222Caption = 'Form1'Color = clBtnFaceFont.Charset = DEFAULT_CHARSETFont.Color = clWindowTextFont.Height = -11Font.Name = 'MS Sans Serif'Font.Style = []OldCreateOrder = FalsePixelsPerInch = 96TextHeight = 13object Button1: TButtonLeft = 128Top = 88Width = 75Height = 25Caption = #25171#24320#31383#20307TabOrder = 0OnClick = Button1Clickendend |
完整的代码如下：
| unit Use_Unit; interface usesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls;typeTForm1 = class(TForm)Button1: TButton;procedure Button1Click(Sender: TObject);private{ Private declarations }public{ Public declarations }end; varForm1: TForm1;procedure LoadForm; external 'usedll.dll' index 1;implementation {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject);beginLoadForm;end; end. |
三、MDI-Child在DLL中载入并使用 如果是MDI-Child又如何在DLL中载入并使用呢，下面就这个问题说说使用DLL文件中封装的窗口。新建一个DLL工程，保存为mdidll，再新建一个窗体，FormStyle设为fsMDIChild，如下：object Form1: TForm1Left = 192Top = 133Width = 344Height = 234Caption = 'MDI'Color = clBtnFaceFont.Charset = DEFAULT_CHARSETFont.Color = clWindowTextFont.Height = -11Font.Name = 'MS Sans Serif'Font.Style = []FormStyle = fsMDIChildOldCreateOrder = FalsePosition = poDefaultVisible = TrueOnClose = FormClosePixelsPerInch = 96TextHeight = 13end
代码如下：
| unit mdi_Unit; interface usesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs; typeTForm1 = class(TForm)procedure FormClose(Sender: TObject; var Action: TCloseAction);private{ Private declarations }public{ Public declarations }MyParentForm: TForm;MyParentApplication: TApplication; end; varDllApplication: TApplication;implementation {$R *.dfm} procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);beginAction:=caFree;end; end. |
| library mdidll; usesWindows,Messages,SysUtils,Classes,Graphics,Controls,Forms,Dialogs,mdi_Unit in 'mdi_Unit.pas' {Form1}; procedure LoadChild(ParentApplication: TApplication; ParentForm: TForm); export; stdcall;varForm1: TForm1;DllProc: Pointer; beginApplication:=ParentApplication;Form1:=TForm1.Create(ParentForm);Form1.MyParentForm:=ParentForm;Form1.MyParentApplication:=ParentApplication;Form1.Show;end; procedure DLLUnloadProc(Reason: Integer); register;beginif Reason = DLL_PROCESS_DETACH then Application:=DllApplication;end; {$R *.res}exportsLoadChild;beginDllApplication:=Application;DLLProc := @DLLUnloadProc;end. |
编译后生成mdidll.dll文件。使用DLL中的MDI-Child窗口如下：
新建一个工程，主窗口设置如下FormStyle设为fsMDIForm：object Form1: TForm1Left = 192Top = 133Width = 544Height = 375Caption = 'Form1'Color = clBtnFaceFont.Charset = DEFAULT_CHARSETFont.Color = clWindowTextFont.Height = -11Font.Name = 'MS Sans Serif'Font.Style = []FormStyle = fsMDIFormMenu = MainMenu1OldCreateOrder = FalsePixelsPerInch = 96TextHeight = 13object MainMenu1: TMainMenuLeft = 72Top = 136object N1: TMenuItemCaption = #26032#24314'(&N)'OnClick = N1Clickendendend代码：
| unit usemdi_Unit; interface usesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, Menus; typeTForm1 = class(TForm)MainMenu1: TMainMenu;N1: TMenuItem;procedure N1Click(Sender: TObject);private{ Private declarations }public{ Public declarations }end;T_ProvaChild = procedure (ParentApplication: TApplication; ParentForm: TForm); stdcall;varForm1: TForm1; implementation {$R *.dfm} procedure TForm1.N1Click(Sender: TObject);varDllHandle: THandle;ProcAddr: FarProc;ProvaChild: T_ProvaChild;begin DllHandle := LoadLibrary('mdidll');ProcAddr := GetProcAddress(DllHandle, 'LoadChild');if ProcAddr <> nil thenbeginProvaChild := ProcAddr;ProvaChild(Application,Self);end;end; end. |
结束语： 到这里你应该会用Delphi调用DLL文件中封装的窗口了吧，如果还有不明白的话请与我联系(主页: http://yousoft.home.chinaren.com ,邮箱:yousoft@chinaren.com)
