以下这段C#代码实现的功能是在屏幕上画图的效果！具体代码如下：

复制代码 代码如下:

//DllImport所在的名字空间

using System.Runtime.InteropServices;

[DllImport("User32.dll")]

public extern static System.IntPtr GetDC(System.IntPtr hWnd);

private void button19_Click(object sender, EventArgs e)

{

System.IntPtr DesktopHandle = GetDC(System.IntPtr.Zero);

Graphics g = Graphics.FromHdc(DesktopHandle);

g.DrawRectangle(new Pen(Color.Red),new Rectangle(10,10,100,100));

}