使用DLL文件中封装的窗口

核心提示：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，使用DLL文件中封装的窗口，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，如下：object Form1: TForm1

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 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. } uses SysUtils, Classes; {$R *.res} begin end.

新建一个窗体，添加一个Label和Button，设置如下：

object Form1: TForm1 Left = 192 Top = 133 Width = 334 Height = 221 Caption = 'DLL'#20013#20351#29992#31383#20307 Color = clBtnFace Font.Charset = DEFAULT_CHARSET Font.Color = clWindowText Font.Height = -11 Font.Name = 'MS Sans Serif' Font.Style = [] OldCreateOrder = False PixelsPerInch = 96 TextHeight = 13 object Label1: TLabel Left = 104 Top = 80 Width = 80 Height = 13 Caption = 'DLL'#20013#20351#29992#31383#20307 end object Button1: TButton Left = 120 Top = 152 Width = 75 Height = 25 Caption = #30830#23450 TabOrder = 0 OnClick = Button1Click end end

添加一过程：procedure LoadForm; export;
procedure LoadForm;
begin
Form1 := TForm1.Create(application);
try
Form1.ShowModal;
finally
Form1.Free;
end;
end; 全部完整的代码：

library usedll; uses SysUtils, Classes, Form_Unit in 'Form_Unit.pas' {Form1}; {$R *.res} exports LoadForm index 1; begin end.

 

unit Form_Unit; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Label1: TLabel; Button1: TButton; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; ApplicationName: String; procedure LoadForm(Handle: THandle; AppName: ShortString); export; implementation {$R *.dfm} procedure LoadForm(Handle: THandle; AppName: ShortString); begin Application.Handle := Handle; ApplicationName := AppName; Form1 := TForm1.Create(Application); try Form1.ShowModal; finally Form1.Free; end; end; procedure TForm1.Button1Click(Sender: TObject); begin self.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: TForm1 Left = 192 Top = 133 Width = 336 Height = 222 Caption = 'Form1' Color = clBtnFace Font.Charset = DEFAULT_CHARSET Font.Color = clWindowText Font.Height = -11 Font.Name = 'MS Sans Serif' Font.Style = [] OldCreateOrder = False PixelsPerInch = 96 TextHeight = 13 object Button1: TButton Left = 128 Top = 88 Width = 75 Height = 25 Caption = #25171#24320#31383#20307 TabOrder = 0 OnClick = Button1Click end end

完整的代码如下：

unit Use_Unit; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; procedure LoadForm; external 'usedll.dll' index 1; implementation {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); begin LoadForm; 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: TForm1
Left = 192
Top = 133
Width = 344
Height = 234
Caption = 'MDI'
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'MS Sans Serif'
Font.Style = []
FormStyle = fsMDIChild
OldCreateOrder = False
Position = poDefault
Visible = True
OnClose = FormClose
PixelsPerInch = 96
TextHeight = 13
end 代码如下：

unit mdi_Unit; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs; type TForm1 = class(TForm) procedure FormClose(Sender: TObject; var Action: TCloseAction); private { Private declarations } public { Public declarations } MyParentForm: TForm; MyParentApplication: TApplication; end; var DllApplication: TApplication; implementation {$R *.dfm} procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction); begin Action:=caFree; end; end.

library mdidll; uses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, mdi_Unit in 'mdi_Unit.pas' {Form1}; procedure LoadChild(ParentApplication: TApplication; ParentForm: TForm); export; stdcall; var Form1: TForm1; DllProc: Pointer; begin Application:=ParentApplication; Form1:=TForm1.Create(ParentForm); Form1.MyParentForm:=ParentForm; Form1.MyParentApplication:=ParentApplication; Form1.Show; end; procedure DLLUnloadProc(Reason: Integer); register; begin if Reason = DLL_PROCESS_DETACH then Application:=DllApplication; end; {$R *.res} exports LoadChild; begin DllApplication:=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: TForm1
Left = 192
Top = 133
Width = 544
Height = 375
Caption = 'Form1'
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'MS Sans Serif'
Font.Style = []
FormStyle = fsMDIForm
Menu = MainMenu1
OldCreateOrder = False
PixelsPerInch = 96
TextHeight = 13
object MainMenu1: TMainMenu
Left = 72
Top = 136
object N1: TMenuItem
Caption = #26032#24314'(&N)'
OnClick = N1Click
end
end
end
代码：

unit usemdi_Unit; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, Menus; type TForm1 = 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; var Form1: TForm1; implementation {$R *.dfm} procedure TForm1.N1Click(Sender: TObject); var DllHandle: THandle; ProcAddr: FarProc; ProvaChild: T_ProvaChild; begin DllHandle := LoadLibrary('mdidll'); ProcAddr := GetProcAddress(DllHandle, 'LoadChild'); if ProcAddr <> nil then begin ProvaChild := 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)