title: Why does Image not appear when rendering it before?
body: <p>Starting with a newly created project I add a button to my main page and do the following in the click handler:</p>
  
  <p>I create an <code>Image</code> and assign a <code>BitmapImage</code> as its <code>Source</code>. Then I add the <code>Image</code> to my <code>LayoutRoot</code>. My expectation is that I see the image in the GUI after I click the button.</p>
  
  <p>Now there is the twist: I also want to render this <code>Image</code> to a <code>WriteableBitmap</code>. Therefore I create such a bitmap and call its <code>Render</code> method to render the image.</p>
  
  <p>Here is the problem: when I comment out the <code>Render</code> call then I immediately see the <code>Image</code> appear on my main page. When I include the <code>Render</code> call, then the Image appears not on the <em>first</em> button click, but on the <em>second</em>. Why?</p>
  
  <p>Here is the code:</p>
  
  <pre><code>    private void button1_Click(object sender, RoutedEventArgs e)
      {
  
          WriteableBitmap wbmp = new WriteableBitmap(62, 62);
          BitmapImage bmp = new BitmapImage(new Uri("ApplicationIcon.png", UriKind.Relative));
          Image img = new Image() { Width = 62, Height = 62, Source = bmp };
  
          wbmp.Render(img, null); // &lt;------ this line makes the difference
  
          LayoutRoot.Children.Add(img);
      }
  </code></pre>