using System.Runtime.InteropServices;

 using System.Drawing.Imaging;

     [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]

     private static extern bool BitBlt(

                     IntPtr hdcDest,   //   目标   DC的句柄

                     int nXDest,

                     int nYDest,

                     int nWidth,

                     int nHeight,

                     IntPtr hdcSrc,     //   源DC的句柄

                     int nXSrc,

                     int nYSrc,

                     System.Int32 dwRop     //   光栅的处理数值

                       ); 

   private   void   button1_Click(object   sender,   System.EventArgs   e)

   {

   //获得当前屏幕的大小   http://www.cnblogs.com/roucheng/

   Rectangle   rect   =   new   Rectangle   (   )   ;

   rect   =   Screen.GetWorkingArea   (   this   )   ;

   //创建一个以当前屏幕为模板的图象

   Graphics   g1   =   this.CreateGraphics   (   )   ;

   //创建以屏幕大小为标准的位图

   Image   MyImage   =   new   Bitmap   (   rect.Width   ,   rect.Height   ,   g1   )   ;

   Graphics   g2   =   Graphics.FromImage   (   MyImage   )   ;

   //得到屏幕的DC

   IntPtr   dc1   =   g1.GetHdc   (   )   ;

   //得到Bitmap的DC

   IntPtr   dc2   =   g2.GetHdc   (   )   ;

   //调用此API函数，实现屏幕捕获

   BitBlt   (   dc2   ,      ,      ,   rect.Width   ,   rect.Height   ,   dc1   ,      ,      ,      )   ;

   //释放掉屏幕的DC

   g1.ReleaseHdc   (   dc1   )   ;

   //释放掉Bitmap的DC

   g2.ReleaseHdc   (   dc2   )   ;

   //以JPG文件格式来保存

   MyImage.Save   (   @"c:/Capture.jpg"   ,   ImageFormat.Jpeg   );

   MessageBox.Show   (   "当前屏幕已经保存为C盘的capture.jpg文件！"   )   ;

   }