1     public class BitMapCaptureScreen 2     { 3         [DllImport("GDI32.dll")] 4         public static extern bool BitBlt(int hdcDest,int nXDest,int nYDest,int nWidth,int nHeight,int hdcSrc,int nXSrc,int nYSrc,int dwRop); 5         [DllImport("GDI32.dll")] 6         public static extern int CreateCompatibleBitmap(int hdc, int nWidth, int nHeight); 7         [DllImport("GDI32.dll")] 8         public static extern int CreateCompatibleDC(int hdc); 9         [DllImport("GDI32.dll")]10         public static extern bool DeleteDC(int hdc);11         [DllImport("GDI32.dll")]12         public static extern bool DeleteObject(int hObject);13         [DllImport("GDI32.dll")]14         public static extern int GetDeviceCaps(int hdc, int nIndex);15         [DllImport("GDI32.dll")]16         public static extern int SelectObject(int hdc, int hgdiobj);17         [DllImport("User32.dll")]18         public static extern int GetDesktopWindow();19         [DllImport("User32.dll")]20         public static extern int GetWindowDC(int hWnd);21         [DllImport("User32.dll")]22         public static extern int ReleaseDC(int hWnd, int hDC);23 24         // Captures the current on-screen representation using Windows API calls25         public Bitmap CaptureScreen()26         {27             // Provides a pointer to the visual representation of the desktop window28             int source = GetWindowDC(GetDesktopWindow());29             // Secures the image using CreateCompatibleBitmap30             int bitmap = CreateCompatibleBitmap(source, GetDeviceCaps(source,8), GetDeviceCaps(source,10));31 32             int destination = CreateCompatibleDC(source);33     34             SelectObject(destination, bitmap);35             BitBlt(destination,0,0, GetDeviceCaps(source,8), GetDeviceCaps(source,10), source,0,0,0x00CC0020);36             Bitmap image = GetImage(bitmap);37             // Save the image as a file.38             image.Save("c:\\capturescreen.jpg", System.Drawing.Imaging.ImageFormat.Gif);39             Cleanup(bitmap, source, destination);40             return image;41         }42 43         private void Cleanup(int bitmap,int source,int destination)44         {45             ReleaseDC(GetDesktopWindow(), source);46             DeleteDC(destination);47             DeleteObject(bitmap);48         }49 50         private Bitmap GetImage(int hBitmap)51         {52             Bitmap image = new Bitmap(Image.FromHbitmap(new IntPtr(hBitmap)), Image.FromHbitmap(new IntPtr(hBitmap)).Width,53             Image.FromHbitmap(new IntPtr(hBitmap)).Height);54             return image;55         }56 57     }