Delphi 製作 .dll 動態鏈接庫，封裝常用的函數。
1，創建 dll 文件：
建立工程 文件 MyDll.dpr：
library Mydll;
uses
SysUtils, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;
{$R *.RES}
//EXE file Full path:
Function appPath(): Pchar; stdcall;
begin
result := Pchar(extractFilepath(application.ExeName));
end;
/////
procedure myMsg(Const sMsg: Pchar); stdcall;
begin
ShowMessage(sMsg);
end;
////////信息框定義：
function myMsgBox(Prompt,Wincaption:Pchar; btnType:integer): integer; stdcall;
begin
result :=Application.MessageBox(Prompt, Wincaption, btnType);
end;
/////
function myLeftStr(str: Pchar; i: integer): Pchar; stdcall;
begin
result :=Pchar(copy(str,1,i));
end;
/////
function myRightStr(str: Pchar; i: integer): Pchar; stdcall;
begin
result :=Pchar(copy(str,length(str)-i+1,255));
end;
////////////
function mySpaces(n: integer): Pchar; stdcall;
var
i: integer;
s: string;
begin
if n<=0 then
begin
result := Pchar('');
exit;
end;
s := '';
for i := 1 to n do
s := s + ' ';
result := Pchar(s);
end;
exports //函數輸出口定義
appPath name 'appPath',
myMsg name 'Msg',
myMsgBox name 'MsgBox',
myLeftStr name 'LeftStr',
myRightStr name 'RightStr',
mySpaces name 'Spaces';
begin
end.
按 Ctrl+F9編譯，生成 mydll.dll 文件。
2，調用 dll:
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
unction myAppPath():Pchar; stdcall; External 'Mydll.dll' name 'appPath';
function myMsg(s:Pchar):Pchar; stdcall; External 'Mydll.dll' name 'Msg';
function myMsgBox(s1,s2:Pchar; btnType:integer):Pchar; stdcall; External 'Mydll.dll' name 'MsgBox';
function myLeftStr(s:Pchar; n:integer):Pchar; stdcall; External 'Mydll.dll' name 'LeftStr';
function myRightStr(s:Pchar; n:integer):Pchar; stdcall; External 'Mydll.dll' name 'RightStr';
function mySpaces(n: integer):Pchar; stdcall; External 'Mydll.dll' name 'Spaces';
type
TForm1 = class(TForm)
Edit1: TEdit;
Button1: TButton;
Button2: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
Tmyspc = function(n: integer): Pchar;
var
Form1: TForm1;
implementation
{$R *.dfm}
//靜態調用
procedure TForm1.Button1Click(Sender: TObject);
begin
Edit1.Text := myAppPath();
myMsg('test myMsg ...');
myMsgBox('test myMsgBox ...', 'win-caption', 0);
Edit1.Text := myLeftStr('123456789', 3); //123
Edit1.Text := myRightStr('123456789', 3); //789
Edit1.Text := 'AAA' + mySpaces(5) + 'BBB'; //AAA BBB
end;
end.
注意：函數的參數和返回值爲 string 類型時，用 pchar 代替。
代碼測試環境：
操作系統：Windows Server 2003，Delphi7.0
作者：張慶(網眼) 西安 PHP 教育培訓中心 2010-9-3
來自“網眼視界”：http://blog.why100000.com
作者微博：http://t.qq.com/zhangking
“十萬個爲什麼”電腦學習網：http://www.why100000.com