title: Overwrite ListBoxitem?
body: <p>I'm new to WPF and I have this ListBox which I want to instantiate with a specific ListBoxItem, so the user knows what to do with the ListBox.</p>
  
  <pre><code> &lt;ListBox Name="DbListBox"
               Grid.Column="3"
               HorizontalAlignment="Left"
               Height="246"
               Margin="0,99,0,0"
               Grid.Row="1"
               VerticalAlignment="Top"
               Width="211"
               SelectionMode="Single"
               SelectedItem="{Binding Path=selectedDB,Mode=TwoWay}" 
               AllowDrop="True"
               Drop="DbListBox_Drop"&gt;
          &lt;ListBoxItem Name="ListBoxItem" FontStyle="Italic"&gt;Drag .db file here or add below&lt;/ListBoxItem&gt;
      &lt;/ListBox&gt;
  </code></pre>
  
  <p>Then I have some code which adds a collection of items to the ItemsSource of this ListBox, but I can't do that since the ItemsSource is not empty</p>
  
  <pre><code>DbListBox.ItemsSource = DbCollection;
  </code></pre>
  
  <p>My question is, how can I start up the ListBox with the item inserted first, and then when DbCollection is added to it, it simply overwrites the first ListBoxItem?</p>