调用Dll里面的窗体

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;
//-------------------------------------------------------------------------------
procedure Dll_Showform();stdcall;external ‘project2.dll‘; //1无参数 直接调用
procedure Dll_Createform(Left,Top,Width,Height:Integer);stdcall;external ‘project2.dll‘;//2带参数了
function DLL_GetValue():string;stdcall;external ‘project2.dll‘;//3获得返回值
//-------------------------------------------------------------------------------

type
  TfrmMain1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Memo1: TMemo;
    Button4: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmMain1: TfrmMain1;

implementation

{$R *.dfm}
//------------------------------------------------------------------------------
procedure TfrmMain1.Button1Click(Sender: TObject);
begin
    Dll_Showform;
end;
//------------------------------------------------------------------------------
procedure TfrmMain1.Button2Click(Sender: TObject);
var
     x,y:Integer;
begin
    x:=frmMain1.left+Button2.left+8; //Left
    y:=frmMain1.Top+Button2.Top +Button2.Height+28;      //Top
    Dll_Createform(x,y,400,400);
    //  Dll_Createform(0,0,100,200);
end;
//------------------------------------------------------------------------------
procedure TfrmMain1.Button3Click(Sender: TObject);
begin
     Memo1.Text:=DLL_GetValue;
end;

//------------------------------------------------------------------------------
type
    TSetCaption = procedure(text:string); stdcall;//4回调
procedure TfrmMain1.Button4Click(Sender: TObject);
var
    pSetTitle: TSetCaption;
    h:THandle;
begin
    h:=LoadLibrary(PChar(‘project2.dll‘));
    pSetTitle := TSetCaption( GetProcAddress(h, PChar(‘DLL_SetTitle‘)) );
    if h = 0 then Exit;
    if Assigned(pSetTitle) then
        pSetTitle(‘Hello World!‘);
    FreeLibrary(h);
end;

end.