title: WebView DefaultBackgroundColor Transparent does not render to WebViewBrush
body: <p>I have a transparent background webview that occasionally I need to interact over (for inking). When I switch to the webviewbrush the webviewbrush renders the transparency as black. I am wondering how to get render transparent:
  C# Code:</p>
  <pre><code>private void MyInkToolbar_ActiveToolChanged(InkToolbar toolbar, object sender)
          {
              if (myInkToolbar.ActiveTool == objectSelect)
              {
                  textCanvas.IsHitTestVisible = true;
                  testTiny.Visibility = Visibility.Visible;
                  testTinyOverlay.Visibility = Visibility.Collapsed;
  
              }
              else
              {
                  if (textCanvas.IsHitTestVisible == true)
                  {
                      testTinyOverlay.Visibility = Visibility.Visible;
                      CaptureWebView();
                      testTiny.Visibility = Visibility.Collapsed;
                      textCanvas.IsHitTestVisible = false;
                  }
              }
          }
          private void CaptureWebView()
          {
              WebViewBrush b = new WebViewBrush();
              b.SetSource(testTiny);
              b.Redraw();
              testTinyOverlay.Fill = b;
          }
  </code></pre>
  <p>Xaml Code:</p>
  <pre><code>&lt;Canvas x:Name=&quot;textCanvas&quot;&gt;
                          &lt;Grid Name=&quot;testTinyGrid&quot; Width=&quot;200&quot; Height=&quot;200&quot; Background=&quot;Transparent&quot;&gt;
                              &lt;Rectangle x:Name=&quot;testTinyOverlay&quot; Fill=&quot;Transparent&quot;/&gt;
                              &lt;WebView x:Name=&quot;testTiny&quot; DefaultBackgroundColor=&quot;Transparent&quot; Source=&quot;ms-appx-web:///HTML/TinyEditor.html&quot;/&gt;
                          &lt;/Grid&gt;
                      &lt;/Canvas&gt;
  </code></pre>
  <p><a href="https://i.stack.imgur.com/Y3mvB.png" rel="nofollow noreferrer">Webview Render Image</a></p>
  <p><a href="https://i.stack.imgur.com/1bWuh.png" rel="nofollow noreferrer">WebViewBrush Render Image</a></p>