C# 在屏幕指定位置绘制，在指定位置显示图片

运用到Graphics类，可以参阅该类的详解。

[DllImport("User32.dll")]
        public extern static System.IntPtr GetDC(System.IntPtr hWnd);            

            System.IntPtr DesktopHandle = GetDC(System.IntPtr.Zero);
            Graphics g = Graphics.FromHdc(DesktopHandle);
            Rectangle ScreenArea = System.Windows.Forms.Screen.GetBounds(this);

            g.DrawRectangle(new Pen(Color.Red), new Rectangle(ScreenArea.Width / 2, ScreenArea.Height / 2, 50, 50));//绘制矩形
            g.DrawIcon(new Icon(@"C:\...\XX.ico"), new Rectangle(ScreenArea.Width / 2, ScreenArea.Height / 2, 30, 30));//ico图标
            g.DrawImage(new Bitmap(@"C:\...\XX.png"), new Rectangle(ScreenArea.Width / 2, ScreenArea.Height / 2, 30, 30));//图片