title: WPF Grid Center and Stretch Textbox
body: <p>I have a WPF grid with row and column 0 as labels. I want the first column to be a static value of 20, but I want the rest of the columns to stretch to their available space until they hit the max width and I want the grid to remain centered even after the rows have hit their max. If I use Grid HorizontalAlignment="Center" each column width is equal to the width of the content of that row, which doesn't look very good for a column full of empty text boxes. If I use Grid HorizontalAlignment="Stretch" it does exactly what I want it to but the Grid isn't centered after the columns have reached their max width, it's left aligned. Is there any way to center the grid and stretch the columns? Attached is a section of the xaml for my grid.</p>
  
  <p>Thanks.</p>
  
  <pre><code>&lt;Expander Margin="10,10,10,10" Header="Expander"&gt;
      &lt;Grid Margin="10,10,10,10" HorizontalAlignment="Center"&gt;
          &lt;Grid.ColumnDefinitions&gt;
              &lt;ColumnDefinition Width="20" /&gt;
              &lt;ColumnDefinition Width="*" MaxWidth="200"/&gt;
              &lt;ColumnDefinition Width="*" MaxWidth="200" /&gt;
              &lt;ColumnDefinition Width="*" MaxWidth="200" /&gt;
           &lt;/Grid.ColumnDefinitions&gt;
           &lt;Grid.RowDefinitions&gt;
               &lt;RowDefinition /&gt;
               &lt;RowDefinition /&gt;
           &lt;/Grid.RowDefinitions&gt;
           &lt;Label Content="Ax" HorizontalContentAlignment="Center" Grid.Column="1" Grid.Row="0"/&gt;
           &lt;Label Content="0" HorizontalContentAlignment="Center" VerticalAlignment="Center" Grid.Column="0" Grid.Row="1" /&gt;
           &lt;TextBox Name="AxK00" Margin="1,1,1,1" HorizontalContentAlignment="Center" Grid.Column="1" Grid.Row="1" /&gt;
           &lt;TextBox Name="AyK00" Margin="1,1,1,1" HorizontalContentAlignment="Center" Grid.Column="2" Grid.Row="1" /&gt;
           &lt;TextBox Name="AzK00" Margin="1,1,1,1" HorizontalContentAlignment="Center" Grid.Column="3" Grid.Row="1" /&gt;
      &lt;/Grid&gt;
  &lt;/Expander&gt;
  </code></pre>