绘制窗口到图像文件

任何人都知道为什么这会一直返回一个空白图片 我在这里find了这个函数。

我传递一个记事本进程/窗口的句柄。

public static Image DrawToBitmap(IntPtr handle) { Bitmap image = new Bitmap(500, 500, System.Drawing.Imaging.PixelFormat.Format32bppArgb); using (Graphics graphics = Graphics.FromImage(image)) { IntPtr hDC = graphics.GetHdc(); SendMessage(new HandleRef(graphics, handle), WM_PRINT, hDC, PRF_CHILDREN); graphics.ReleaseHdc(hDC); } return image; } 

我利用上面这样的:

 Image myimage = DrawToBitmap(handle); myimage.Save("C:\\here.png", ImageFormat.Png); 

感谢所有的帮助

更新

我想我已经设法从SendMessage使用下面的错误代码:

 if (SendMessage(handle, WM_PRINT, hDC, PRF_CLIENT)) { Console.WriteLine("Success!"); } else { Console.WriteLine("Error: " + Marshal.GetLastWin32Error()); } 

我得到一个8的错误,我发现这意味着没有足够的内存? 我有超过500MB的免费! 也许我正在理解这个错误?

而不是SendMessage你可以使用PrintWindow

这里是一个例子

 public static Image DrawToBitmap(IntPtr handle) { RECT rect = new RECT(); GetWindowRect(handle, ref rect); Bitmap image = new Bitmap(rect.Right - rect.Left, rect.Bottom - rect.Top); using (Graphics graphics = Graphics.FromImage(image)) { IntPtr hDC = graphics.GetHdc(); PrintWindow(new HandleRef(graphics, handle), hDC, 0); graphics.ReleaseHdc(hDC); } return image; } #region Interop [DllImport("USER32.DLL")] private static extern bool PrintWindow(HandleRef hwnd, IntPtr hdcBlt, int nFlags); [DllImport("user32.dll", SetLastError = true)] [return: MarshalAs(UnmanagedType.Bool)] private static extern bool GetWindowRect(IntPtr hWnd, ref RECT lpRect); [StructLayout(LayoutKind.Sequential)] private struct RECT { public int Left; public int Top; public int Right; public int Bottom; } #endregion 

除PRF_CHILDREN外,尝试将PRF_CLIENT或PRF_NONCLIENT传递给SendMessage。

另外,你如何得到你传递给函数的句柄?