C#實現抓屏

using System; using System.Runtime.InteropServices; using System.Drawing; using System.Drawing.Imaging; namespace ScreenShotDemo {  /// <summary>  /// 提供捕獲全屏或者一個不規則視窗函數，並儲存。  /// </summary>  public class ScreenCapture  {         /// <summary>         /// Creates an Image object containing a screen shot of the entire desktop?         /// </summary>         /// <returns></returns>         public Image CaptureScreen()         {             return CaptureWindow( User32.GetDesktopWindow() );         }         /// <summary>         /// Creates an Image object containing a screen shot of a specific window?         /// </summary>         /// <param name="handle">The handle to the window. (In windows forms, this is obtained by the Handle property)</param>         /// <returns></returns>         public Image CaptureWindow(IntPtr handle)         {             // get te hDC of the target window             IntPtr hdcSrc = User32.GetWindowDC(handle);             // get the size             User32.RECT windowRect = new User32.RECT();             User32.GetWindowRect(handle,ref windowRect);             int width = windowRect.right - windowRect.left;             int height = windowRect.bottom - windowRect.top;             // create a device context we can copy to             IntPtr hdcDest = GDI32.CreateCompatibleDC(hdcSrc);             // create a bitmap we can copy it to,             // using GetDeviceCaps to get the width/height             IntPtr hBitmap = GDI32.CreateCompatibleBitmap(hdcSrc,width,height);             // select the bitmap object             IntPtr hOld = GDI32.SelectObject(hdcDest,hBitmap);             // bitblt over             GDI32.BitBlt(hdcDest,0,0,width,height,hdcSrc,0,0,GDI32.SRCCOPY);             // restore selection             GDI32.SelectObject(hdcDest,hOld);             // clean up             GDI32.DeleteDC(hdcDest);             User32.ReleaseDC(handle,hdcSrc);             // get a .NET image object for it             Image img = Image.FromHbitmap(hBitmap);             // free up the Bitmap object             GDI32.DeleteObject(hBitmap);             return img;         }         /// <summary>         /// Captures a screen shot of a specific window, and saves it to a file?         /// </summary>         /// <param name="handle"></param>         /// <param name="filename"></param>         /// <param name="format"></param>         public void CaptureWindowToFile(IntPtr handle, string filename, ImageFormat format)         {             Image img = CaptureWindow(handle);             img.Save(filename,format);         }         /// <summary>         /// Captures a screen shot of the entire desktop, and saves it to a file?         /// </summary>         /// <param name="filename"></param>         /// <param name="format"></param>         public void CaptureScreenToFile(string filename, ImageFormat format)         {             Image img = CaptureScreen();             img.Save(filename,format);         }                /// <summary>         /// Helper class containing Gdi32 API functions         /// </summary>         private class GDI32         {                         public const int SRCCOPY = 0x00CC0020; // BitBlt dwRop parameter             [DllImport("gdi32.dll")]             public static extern bool BitBlt(IntPtr hObject,int nXDest,int nYDest,                 int nWidth,int nHeight,IntPtr hObjectSource,                 int nXSrc,int nYSrc,int dwRop);             [DllImport("gdi32.dll")]             public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC,int nWidth,                 int nHeight);             [DllImport("gdi32.dll")]             public static extern IntPtr CreateCompatibleDC(IntPtr hDC);             [DllImport("gdi32.dll")]             public static extern bool DeleteDC(IntPtr hDC);             [DllImport("gdi32.dll")]             public static extern bool DeleteObject(IntPtr hObject);             [DllImport("gdi32.dll")]             public static extern IntPtr SelectObject(IntPtr hDC,IntPtr hObject);         }           /// <summary>         /// Helper class containing User32 API functions         /// </summary>         private class User32         {             [StructLayout(LayoutKind.Sequential)]             public struct RECT             {                 public int left;                 public int top;                 public int right;                 public int bottom;             }             [DllImport("user32.dll")]             public static extern IntPtr GetDesktopWindow();             [DllImport("user32.dll")]             public static extern IntPtr GetWindowDC(IntPtr hWnd);             [DllImport("user32.dll")]             public static extern IntPtr ReleaseDC(IntPtr hWnd,IntPtr hDC);             [DllImport("user32.dll")]             public static extern IntPtr GetWindowRect(IntPtr hWnd,ref RECT rect);         }  } }