title: WPF DataGrid Row Header is invisible
body: <p>I have WPF-MVVM DataGrid. I want to use the Row Header But it is invisible.
  I tried to set it with RowHeaderWidth, but it doesn't have any effect.
  Below is my code:</p>
  
  <pre><code>&lt;Grid DataContext="{Binding Tours}"&gt;
    &lt;DataGrid Grid.Row="0"
      x:Name="tourDataGrid" 
      RowHeaderWidth="27"
      ItemsSource="{Binding}" 
      AutoGenerateColumns="False"
      Height="360"&gt;
  </code></pre>
  
  <p>What is wrong ?</p>
  
  <p>Many Thanks in advance...</p>