How to render a WPF UserControl to a bitmap without creating a window
Have you tried spinning up an instance of the user control and doing something like this:
UserControl control = new UserControl1();control.Measure(new Size(300, 300));control.Arrange(new Rect(new Size(300,300)));RenderTargetBitmap bmp = new RenderTargetBitmap(300, 300, 96, 96, PixelFormats.Pbgra32);bmp.Render(control);var encoder = new PngBitmapEncoder();encoder.Frames.Add(BitmapFrame.Create(bmp));using (Stream stm = File.Create(@"c:\test.png")) encoder.Save(stm);It looks like you need to Measure, Arrange. This worked for me.
Ended up using an HwndHost with no actual window.
void cwind() { Application myapp = new Application(); mrenderer = new WPFRenderer(); mrenderer.Width = 256; mrenderer.Height = 256; HwndSourceParameters myparms = new HwndSourceParameters(); HwndSource msrc = new HwndSource(myparms); myparms.HwndSourceHook = new HwndSourceHook(ApplicationMessageFilter); msrc.RootVisual = mrenderer; myapp.Run(); } static IntPtr ApplicationMessageFilter(IntPtr hwnd, int message, IntPtr wParam, IntPtr lParam, ref bool handled) { return IntPtr.Zero; }