只要不是最小化的窗口，无论它被遮挡一部分还是全部，无论它的位置是否超出屏幕边界，都可以抓到 下面是代码：
function PrintWindow(Wnd: HWND; hDCBlt: HDC; nFlags: DWord): Bool; stdcall external 'user32.dll';
var
Cap : string; procedure TForm1.Timer1Timer(Sender: TObject);
var
hBMP : HBITMAP;
DC, DC1 : HDC;
H : hWnd;
R : TRect;
begin
H := FindWindow(nil, PAnsiChar(Cap));
if H > 0 then begin
DC := GetWindowDC(H);
GetWindowRect(H, R);
hBMP := CreateCompatibleBitmap(DC, R.Right-R.Left, R.Bottom-R.Top);
DC1 := CreateCompatibleDC(DC);
SelectObject(DC1, hBMP);
PrintWindow(H, DC1, 0);
//image1.Canvas.Handle:=dc1;
//image1.Refresh;
Self.Image1.Height := Round((R.Bottom-R.Top) * (Self.Image1.Width / (R.Right-R.Left)));
Self.Image1.Picture.Bitmap.Handle:= hBMP;
Self.Image1.Refresh;
DeleteDC(DC1);
DeleteDC(DC);
end;
end; procedure TForm1.FormCreate(Sender: TObject);
begin
//Self.Image1.AutoSize := True;
Self.Left := Screen.Width-Self.Width;
Self.Top := Screen.Height-Self.Height-50;
Self.FormStyle := fsStayOnTop;
Self.Image1.Left := 2;
Self.Image1.Top := 2;
Self.Image1.Width := Self.Width - 100;
Self.Image1.Stretch := True;
Self.Timer1.Enabled := False;
end; procedure TForm1.Button1Click(Sender: TObject);
begin
Cap := Self.Edit1.Text;
Self.Timer1.Interval := 50;
Self.Timer1.Enabled := True;
end; | 
