导入函数

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

              public static extern bool BitBlt(

                     IntPtr hdcDest ,

                     int nXDest ,

                     int nYDest ,

                     int nWidth ,

                     int nHeight ,

                     IntPtr hdcSrc ,

                     int nXSrc ,

                     int nYSrc ,

                     System.Int32 dwRop

                     ) ;

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

              public static extern bool StretchBlt(

                     IntPtr hDC,

                     int x,

                     int y,

                     int nWidth,

                     int nHeight,

                     IntPtr hSrcDC,

                     int xSrc,

                     int ySrc,

                     int nSrcWidth,

                     int nSrcHeight,

                     System.Int32 dwRop);

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

              public static extern IntPtr CreateDC (

                     string lpszDriver,

                     string lpszDevice,

                     string lpszOutput,

                     IntPtr lpInitData

                     );

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

              public static extern bool DeleteDC (

                     IntPtr lpszDriver                 

                     );

抓取函数

              public static byte[] CaptureDisplay()

              {

                     //define variable                   

                     IntPtr dcDisplay;

                     IntPtr dcImage;

                     Graphics gDisplay;

                     Graphics gImage;

                     System.IO.Stream sImage;

                     Image imgDisplay;                                    

                     byte[] bufTemp;                  

                     ImageCodecInfo myImageCodecInfo;

                     Encoder myEncoder;

                     EncoderParameter myEncoderParameter;

                     EncoderParameter myEncoderParameter1;

                     EncoderParameters myEncoderParameters;

                     try

                     {

                            //init variable

                            sImage=new System.IO.MemoryStream();

                            //get display dc

                            dcDisplay= WIN32Api.CreateDC("DISPLAY",null, null, IntPtr.Zero);                     

                            gDisplay=Graphics.FromHdc(dcDisplay);

                            //create image                     

                            imgDisplay = new Bitmap((int)(gDisplay.VisibleClipBounds.Width) ,(int)(gDisplay.VisibleClipBounds.Height));                                      

                            gImage = Graphics.FromImage(imgDisplay);                          

                            //get image hdc

                            dcImage = gImage.GetHdc();

                            //print display to image                                            

                            WIN32Api.StretchBlt( dcImage, 0, 0, (int)(gDisplay.VisibleClipBounds.Width) ,(int)(gDisplay.VisibleClipBounds.Height ), dcDisplay,0,0,Convert.ToInt32(gDisplay.VisibleClipBounds.Width),Convert.ToInt32(gDisplay.VisibleClipBounds.Height), 13369376);

                            //release hdc                       

                            gImage.ReleaseHdc(dcImage);                                                             

                            WIN32Api.DeleteDC(dcDisplay);

                            //encode image

                            myImageCodecInfo=null;

                            foreach(ImageCodecInfo imagecodecinfo in ImageCodecInfo.GetImageEncoders())

                            {                         

                                   if(imagecodecinfo.MimeType=="image/jpeg")

                                   {

                                          myImageCodecInfo=imagecodecinfo;

                                          break;

                                   }

                            }

                            //encoder image

                            //adjust color depth

                            myEncoderParameters=new EncoderParameters(2);

                            myEncoder=Encoder.ColorDepth;                     

                            myEncoderParameter=new EncoderParameter(myEncoder,8L);

                            myEncoderParameters.Param[0]=myEncoderParameter;

                            myEncoder=Encoder.Quality;

                            myEncoderParameter1=new EncoderParameter(myEncoder,25L);

                            myEncoderParameters.Param[1]=myEncoderParameter1;

                            //save image to memory stream                                                     

                            imgDisplay.Save(sImage,myImageCodecInfo,myEncoderParameters);                                                      

                            bufTemp=new byte[sImage.Length];

                            sImage.Position=0;

                            sImage.Read(bufTemp,0,bufTemp.Length);                                   

                            return bufTemp;

                     }

                     catch(Exception exp)

                     {

                            throw exp;

                     }

              }