title: How to delete padding in DataGrid?
body: <p>I don't understand why I have this space (padding) between DataGrid frame and it content. I marked this space in red at the screenshot</p>
  
  <p><a href="https://i.stack.imgur.com/xIJ6dl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xIJ6dl.png" alt="enter image description here"></a></p>
  
  <p>There is a picture without red mark for better viewing </p>
  
  <p><a href="https://i.stack.imgur.com/M10h5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/M10h5.png" alt="enter image description here"></a></p>
  
  <p>It looks a little bit strange... just a space without any reason.</p>
  
  <p>There is my <code>.xalm</code></p>
  
  <pre><code>    &lt;Grid&gt;
          &lt;ScrollViewer&gt;
              &lt;StackPanel HorizontalAlignment="Stretch" 
                      VerticalAlignment="Stretch" &gt;
  
                  &lt;GroupBox Header="Main configuration :" 
                        HorizontalAlignment="Stretch"
                        Height="Auto"&gt;
  
                      &lt;Grid&gt;
                          &lt;Grid.ColumnDefinitions&gt;
                              &lt;ColumnDefinition Width="90*"/&gt;
                              &lt;ColumnDefinition Width="10*"/&gt;
                          &lt;/Grid.ColumnDefinitions&gt;
  
                          &lt;DataGrid ItemsSource="{Binding Path=GridItems}"
                                    HorizontalGridLinesBrush="Gray"
                                    CanUserReorderColumns="False"
                                    CanUserDeleteRows="False"
                                    CanUserResizeRows="False"
                                    CanUserSortColumns="False"
                                    VerticalGridLinesBrush="LightGray"
                                    x:Name="Dg_main_configuration"
                                    CanUserResizeColumns="False"
                                    PreviewMouseLeftButtonUp="Dg_main_configuration_PreviewMouseLeftButtonUp"
                                        AlternatingRowBackground="LightYellow"
                                        CanUserAddRows="False"
                                        MinHeight="150"
                                        MaxHeight="150"
                                        Grid.Column="0"
                                        AutoGenerateColumns="False"&gt;
                              &lt;DataGrid.Columns&gt;
                                  &lt;DataGridTextColumn 
                                      IsReadOnly="True"
                                      Header="Path to calibration folder" 
                                      Binding="{Binding Path=ClipFolder}"/&gt;
  
  ....
  ....
  </code></pre>
  
  <p>As you can see there is any line about padding or margin....</p>
  
  <p>What am I doing wrong?</p>