unitmain.pas

在delphi中实现windows核心编程.原书光盘代码核心编程.原书光盘代码

unit UnitMain;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls,wjsthunk;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  DLLHandle: THandle;
  ProcAddress: Pointer; {函数指针}
  
implementation

{$R *.DFM}

function proc32:boolean;
begin
    DLLHandle := LoadLibrary16('MyDll.DLL');
    if DLLHandle<32 then raise exception.create('MyDll.DLL没找到');
    ProcAddress := GetProcAddress16(DLLHandle, 'Proc16');
    if ProcAddress=nil then
    begin
      FreeLibrary16(DLLHandle);
      raise exception.create('指定的函数没找到');
    end;
    result:=false;
    asm  //以下汇编代码中，只有第一参数、第二参数、pFunc的值是需要改变的，
         //其余都是固定的写法
      pushad
      push es
      push ds
      push ebp           //#2，保存ebp
      sub esp,$2c        //#1，预留2c字节的栈空间
      mov edx,ProcAddress//函数地址
      mov ebp,esp        //#0
      add ebp,$2c        //#0，ebp放至2c字节栈的顶部
      call QT_Thunk
      add esp,$2c        //#1，释放上面预留的2c字节的栈空间
      pop ebp            //#2，恢复ebp
      mov byte ptr @result,al //result前要加上@
      pop ds
      pop es
      popad
    end;
    if result then showmessage('OK!');
    FreeLibrary16(DLLHandle);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
    proc32;
end;

end.