使用DLL文件中封装的窗口计算机等级考试

文章作者 100test 发表时间 2010:01:01 09:29:57
来源 100Test.Com百考试题网

　　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 (0select
　　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).