截屏

Screen sc = Screen.PrimaryScreen;
Rectangle rct = sc.Bounds;
Image img = new Bitmap(rct.Width, rct.Height);
Graphics gp = Graphics.FromImage(img);
gp.CopyFromScreen(new Point(0, 0), new Point(0, 0), new Size(rct.Width, rct.Height));

SolidBrush sb = new SolidBrush(Color.Red);
Font ft = new System.Drawing.Font("黑体", 16);

gp.DrawString("这是什么", ft, sb, new PointF(0, rct.Height - ft.Height));

this.pictureBox1.Image = img;