title: Checkbox is not checked in DevExpress GridControl using wpf
body: <p>I am trying to work on DevExpress GridControl Checkbox column but problem is that when I binding the checkbox value in XAML code dynamically its not work perfectlly 
  below I provide you my demo project code :-</p>
  
  <p>XAML Code:-</p>
  
  <pre><code>&lt;dxg:GridControl AutoPopulateColumns="True" HorizontalAlignment="Left"  Margin="0,40,0,0" Name="gridControl1" VerticalAlignment="Top" Height="318" Width="503"&gt;
              &lt;dxg:GridControl.View&gt;
                  &lt;dxg:TableView Name="tableView1" ShowTotalSummary="True" /&gt;
              &lt;/dxg:GridControl.View&gt;
              &lt;dxg:GridControl.Columns&gt;
                  &lt;dxg:GridColumn DisplayMemberBinding="{Binding Path=EvenOdd}" Header="Even/Odd" /&gt;
                  &lt;dxg:GridColumn Name="PickColumn" Header="Pick" Width="30" 
                                      AllowColumnFiltering="False" AllowSorting="False"&gt;
                      &lt;dxg:GridColumn.CellTemplate&gt;
                          &lt;DataTemplate&gt;
                              &lt;CheckBox IsChecked="{Binding Path=IsValid}"
                                            HorizontalAlignment="Center" VerticalAlignment="Center" &gt;
                              &lt;/CheckBox&gt;
                          &lt;/DataTemplate&gt;
                      &lt;/dxg:GridColumn.CellTemplate&gt;
                  &lt;/dxg:GridColumn&gt;
              &lt;/dxg:GridControl.Columns&gt;
          &lt;/dxg:GridControl&gt;
  </code></pre>
  
  <p>my cs file code:-</p>
  
  <pre><code>public class ss
  {
    public bool IsValid { get; set; }
    public string EvenOdd { get; set; }
  }
  </code></pre>
  
  <p>Code Behind:</p>
  
  <pre><code>    public List&lt;ss&gt; sList = new List&lt;ss&gt;();
  
  
      private void Window_Loaded(object sender, RoutedEventArgs e)
      {
  
          for (int i = 0; i &lt; 10; i++)
          {
  
              if (i % 2 == 0)
              {
                  sList.Add(new ss { IsValid = true, EvenOdd = "Even" });
              }
              else
              {
                  sList.Add(new ss { IsValid = false, EvenOdd = "Odd" });
              }
          }
  
         gridControl1.ItemsSource = sList;
      }
  </code></pre>