原文：http://www.cnblogs.com/del/archive/2008/06/17/1223681.html

unit Unit1;

interface

uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;

type

  TForm1 = class(TForm)

    Button1: TButton;

    procedure FormCreate(Sender: TObject);

    procedure Button1Click(Sender: TObject);

  end;

var

  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var

  buf: array[..MAX_PATH] of Char;

  hinst: HMODULE;
begin

  {获取指定模块的句柄}

  hinst := GetModuleHandle('gdi32.dll');

  {获取模块的路径}

  GetModuleFileName(hinst, buf, Length(buf));

  ShowMessage(buf); {C:\WINDOWS\system32\GDI32.dll}
end;

procedure TForm1.Button1Click(Sender: TObject);
var

  buf: array[..MAX_PATH] of Char;
begin

  {当 GetModuleFileName 的第一个参数为 0 或 HInstance 时, 会获取当前模块路径}

  GetModuleFileName(, buf, Length(buf));

  ShowMessage(buf);

  GetModuleFileName(HInstance, buf, Length(buf));

  ShowMessage(buf);

  {获取当前程序路径的常用方法}

  ShowMessage(Application.ExeName);

  ShowMessage(ParamStr());
end;

end.