delphi 屏幕截屏

function GetScreenAll: TBitmap; // 截取全屏
var
  C: TCanvas;
begin
  C := TCanvas.Create;
  result := TBitmap.Create;
  result.Width  := Screen.Width;
  result.Height := Screen.Height;
  C.Handle := GetDC(0);  // 获取屏幕的设备上下文句柄，并拷贝
  result.Canvas.CopyRect(Rect(0, 0, screen.Width, screen.Height), C, Rect(0, 0, Screen.Width, SCreen.Height));
  ReleaseDC(0, C.Handle);
  C.Free;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  B: TBitmap;
begin
  B := TBitmap.Create;
  B := GetScreenAll();
  B.SaveToFile('d:\test2.bmp');
  b.Free;
end;