I am trying to capture the content of the WebBrowser control. DrawToBitmap()
would work perfectly, but it is not supported in documentation for the WebBrowser control. I have been trying to find another way to capture the contents of the WebBrowser control and save them to a local image file.
Does anyone have any workarounds or other methods to save the contents of the WebBrowser control to a local image file?
The Control.DrawToBitmap doesn't always work so I resorted to the following native API calls that provide more consistent results:
The Utilities class. Call Utilities.CaptureWindow(Control.Handle) to capture a specific control:
public static class Utilities
{
public static Image CaptureScreen()
{
return CaptureWindow(User32.GetDesktopWindow());
}
public static Image CaptureWindow(IntPtr handle)
{
IntPtr hdcSrc = User32.GetWindowDC(handle);
RECT windowRect = new RECT();
User32.GetWindowRect(handle, ref windowRect);
int width = windowRect.right - windowRect.left;
int height = windowRect.bottom - windowRect.top;
IntPtr hdcDest = Gdi32.CreateCompatibleDC(hdcSrc);
IntPtr hBitmap = Gdi32.CreateCompatibleBitmap(hdcSrc, width, height);
IntPtr hOld = Gdi32.SelectObject(hdcDest, hBitmap);
Gdi32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, ApiConstants.SRCCOPY);
Gdi32.SelectObject(hdcDest, hOld);
Gdi32.DeleteDC(hdcDest);
User32.ReleaseDC(handle, hdcSrc);
Image image = Image.FromHbitmap(hBitmap);
Gdi32.DeleteObject(hBitmap);
return image;
}
}
The Gdi32 class:
public class Gdi32
{
[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);
}
The User32 class:
public static class User32
{
[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 GetWindowRect(IntPtr hWnd, ref RECT rect);
[DllImport("user32.dll")]
public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
}
The constants used:
public const int SRCCOPY = 13369376;
The structs used:
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
}
A friendly Control extension method:
public static class ControlExtensions
{
public static Image DrawToImage(this Control control)
{
return Utilities.CaptureWindow(control.Handle);
}
}
This is a code snippet from my CC.Utilities project and I specifically wrote it to take screenshots from the WebBrowser control.