title: Inheriting Silverlight 3 control does not initialize content
body: <p>I have a silverlight custom control named "BASE".  I have another control that inherits from this class, "CHILD1".  BASE has a ContentPresenter that holds the content from the CHILD1 control.  I need to access a TextBox that is in the content of the CHILD1 control, it initiailzes, and displays, but it is always null in the code.</p>
  
  <p>Is there a way to access these controls directly instead of iterating over the children collection of the content property?</p>
  
  <p>Thanks.</p>
  
  <p>CHILD1:</p>
  
  <pre><code>&lt;local:BASE x:Class="CWTest1.CHILD1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:local="clr-namespace:CWTest"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             Width="400"
             Height="300"&gt;
  &lt;Grid x:Name="LayoutRoot2"
        Background="White"&gt;
      &lt;TextBox x:Name="tbx1"
               Text="xx" /&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p></p>
  
  <pre><code>public partial class CHILD1 : BASE
  {
      public CHILD1()
      {
          InitializeComponent();
  
          // this.tbx1 is always null
          this.tbx1.Focus();
      }
  }
  </code></pre>
  
  <p>Part of BASE:</p>
  
  <pre><code>&lt;ContentPresenter Grid.Row="1"
                        x:Name="cprContent"
                        Content="" /&gt;
  </code></pre>
  
  <p>Base class code:-</p>
  
  <pre><code>[ContentProperty("Content")]
  public partial class cwBase1 : ChildWindow
  ...
  new public object Content
      {
          get { return cprContent.Content; }
          set { cprContent.Content = value; }
      }
  </code></pre>