c#截取后台窗口的图片，自测可用，据说性能很一般，用用吧
1 struct RECT 2 { 3 public int Left; // x position of upper-left corner 4 public int Top; // y position of upper-left corner 5 public int Right; // x position of lower-right corner 6 public int Bottom; // y position of lower-right corner 7 } 8 public static Bitmap GetWindow(IntPtr hWnd) 9 { 10 IntPtr hscrdc = GetWindowDC(hWnd); 11 RECT rect = new RECT(); 12 GetWindowRect(hWnd, out rect); 13 IntPtr hbitmap = CreateCompatibleBitmap(hscrdc, rect.Right - rect.Left, rect.Bottom - rect.Top); 14 IntPtr hmemdc = CreateCompatibleDC(hscrdc); 15 SelectObject(hmemdc, hbitmap); 16 PrintWindow(hWnd, hmemdc, 0); 17 Bitmap bmp = Bitmap.FromHbitmap(hbitmap); 18 DeleteDC(hscrdc); 19 DeleteDC(hmemdc); 20 return bmp; 21 } 22 23 //API声明 24 25 [DllImport("user32.dll")] 26 private static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect); 27 28 [DllImport("gdi32.dll")] 29 public static extern IntPtr CreateDC( 30 string lpszDriver, // driver name驱动名 31 string lpszDevice, // device name设备名 32 string lpszOutput, // not used; should be NULL 33 IntPtr lpInitData // optional printer data 34 ); 35 36 [DllImport("gdi32.dll")] 37 public static extern int BitBlt( 38 IntPtr hdcDest, // handle to destination DC目标设备的句柄 39 int nXDest, // x-coord of destination upper-left corner目标对象的左上角的X坐标 40 int nYDest, // y-coord of destination upper-left corner目标对象的左上角的Y坐标 41 int nWidth, // width of destination rectangle目标对象的矩形宽度 42 int nHeight, // height of destination rectangle目标对象的矩形长度 43 IntPtr hdcSrc, // handle to source DC源设备的句柄 44 int nXSrc, // x-coordinate of source upper-left corner源对象的左上角的X坐标 45 int nYSrc, // y-coordinate of source upper-left corner源对象的左上角的Y坐标 46 UInt32 dwRop // raster operation code光栅的操作值 47 ); 48 49 [DllImport("gdi32.dll")] 50 public static extern IntPtr CreateCompatibleDC( 51 IntPtr hdc // handle to DC 52 ); 53 54 [DllImport("gdi32.dll")] 55 public static extern IntPtr CreateCompatibleBitmap( 56 IntPtr hdc, // handle to DC 57 int nWidth, // width of bitmap, in pixels 58 int nHeight // height of bitmap, in pixels 59 ); 60 61 [DllImport("gdi32.dll")] 62 public static extern IntPtr SelectObject( 63 IntPtr hdc, // handle to DC 64 IntPtr hgdiobj // handle to object 65 ); 66 67 [DllImport("gdi32.dll")] 68 public static extern int DeleteDC( 69 IntPtr hdc // handle to DC 70 ); 71 72 [DllImport("user32.dll")] 73 public static extern bool PrintWindow( 74 IntPtr hwnd, // Window to copy,Handle to the window that will be copied. 75 IntPtr hdcBlt, // HDC to print into,Handle to the device context. 76 UInt32 nFlags // Optional flags,Specifies the drawing options. It can be one of the following values. 77 ); 78 79 [DllImport("user32.dll")] 80 public static extern IntPtr GetWindowDC( 81 IntPtr hwnd 82 );