Delphi模拟最小化恢复关闭按纽(2)

procedure TFrmMain.ApplicationEvents1Idle(Sender: TObject;
var Done: Boolean);
var
show: boolean;
begin
//当前子窗体的状态为最大化时,显示三个按纽
show := (self.ActiveMDIChild <> nil) and (self.ActiveMDIChild.WindowState =
wsMaximized);
if assigned(BtnClose) and BtnClose.Visible <> Show then
BtnClose.Visible := Show;
if assigned(BtnMin) and BtnMin.Visible <> Show then
BtnMin.Visible := Show;
if assigned(BtnRestore) and BtnRestore.Visible <> Show then
BtnRestore.Visible := Show;
end;

//设置按纽的相对位置不变

procedure TfrmMain.SetMDIFormActionPos;
begin
if assigned(BtnClose) then
begin
BtnClose.left := Width - 26;
BtnClose.top := 6;
end;
if assigned(BtnRestore) then
begin
BtnRestore.Left := Width - 44;
BtnRestore.Top := 6;
end;
if assigned(BtnMin) then
begin
BtnMin.Left := Width - 60;
BtnMin.Top := 6;
end;
end;

procedure TFrmMain.FormResize(Sender: TObject);
begin
SetMDIFormActionPos;
end;

procedure TFrmMain.FormDestroy(Sender: TObject);
begin
//释放资源
if assigned(BtnClose) then
begin
WindowClose.ActionList := nil;
WindowClose.free;
BtnClose.Free;
BtnClose := nil;
end;
if assigned(BtnRestore) then
begin
WindowRestore.ActionList := nil;
WindowRestore.free;
BtnRestore.Free;
BtnRestore := nil;
end;
if assigned(BtnMin) then
begin
WindowMinimize.ActionList := nil;
WindowMinimize.free;
BtnMin.Free;
BtnMin := nil;
end;
end;

{ TWindowRestore }

procedure TWindowRestore.ExecuteTarget(Target: TObject);
begin
inherited;
with GetForm(Target) do
ActiveMDIChild.WindowState := wsnormal;
end;

{ TMDIButton }

procedure TMDIButton.wndproc(var message: Tmessage);
begin
if message.msg = wm_SetFocus then exit;
inherited wndproc(message);
end;

{ TWindowMinimize }

procedure TWindowMinimize.ExecuteTarget(Target: TObject);
begin
inherited;
with GetForm(Target) do
ActiveMDIChild.WindowState := wsMinimized;
end;

procedure TFrmMain.open1Click(Sender: TObject);
begin
with Tform.create(self) do
begin
formstyle := fsMDIChild;
end;
end;

end.