Bitmap bitmap = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);

            Graphics g = Graphics.FromImage(bitmap);

            g.CopyFromScreen(new Point(0, 0), new Point(0, 0), Screen.PrimaryScreen.Bounds.Size);

            bitmap.Save(Application.StartupPath + @"\截图.png");

            bitmap.Dispose();

            bitmap.Dispose();