Iterate/Loop through Datagrid rows to get the value of checkbox column using Silverlight/ c# wpf: NullReferenceException error

[Sarvesh]

I have a DataGrid in Silverlight xaml which contains three columns named Active(checkbox), name(Textcolumn), ID (Textcolumn) and a Save button outside the datagrid. I am getting the following error when I try to loop/iterate through the datagrid rows to get the value of the checkbox using GetCellContent. GetCellContent works fine for first 20 rows but gives the NullReferenceException error after that. Please help. 

    System.NullReferenceException: Object reference not set to an instance of an object.

XAML

    <StackPanel Orientation="Horizontal">
                        <Button Content ="Save" Click="SavePopUp_Click"/>
                        <TextBlock x:Name="GridHeader"  Style="{StaticResource GridHeaderStyle}" Margin="0,0,0,0" Width="445" Foreground="White" HorizontalAlignment="Right" TextAlignment="Center" Visibility="Collapsed"/>
    </StackPanel>
    
    <sdk:DataGrid  x:Name="dgloss">
    <sdk:DataGrid.RowDetailsTemplate>
                    <DataTemplate>
                          <Border>
                               <Border Margin="2" Padding="2" BorderBrush="#AAAAAA" BorderThickness="2" CornerRadius="4">
                      </Border>
                    </Border>
                    </DataTemplate>
            </sdk:DataGrid.RowDetailsTemplate>
    
            <sdk:DataGrid.Columns>
                           
             <!--<sdk:DataGridCheckBoxColumn  IsReadOnly="False" Header="Active" Binding="{Binding Active, Mode=TwoWay}" CanUserResize="False" />-->
                            <sdk:DataGridTemplateColumn Header ="Active">
                                <sdk:DataGridTemplateColumn.CellTemplate>
                                    <DataTemplate>
                                        <CheckBox x:Name="chkcode" Tag="{Binding Active}" Checked="HandleCheck" Unchecked="HandleUnchecked" IsThreeState="False" HorizontalAlignment ="Center" VerticalAlignment="Center" IsChecked="{Binding Active, Mode=TwoWay}" />
                                    </DataTemplate>
                                </sdk:DataGridTemplateColumn.CellTemplate>
                                </sdk:DataGridTemplateColumn>
    
                                <sdk:DataGridTextColumn IsReadOnly="True" SortMemberPath="Name" Header="Name" Binding="{Binding Name, Mode=TwoWay}" Foreground="White"/>
                            <sdk:DataGridTextColumn x:Name="ID" IsReadOnly="True" SortMemberPath="ID" Header="ID" Binding="{Binding ID, Mode=TwoWay}" Foreground="White" Visibility="Visible"/>
             </sdk:DataGrid.Columns>
    
    </sdk:DataGrid>



---------------------------------------------------------------


**Save button Click event**


        private void SavePopUp_Click(object sender, RoutedEventArgs e)
                {
                   IEnumerable list = dgloss.ItemsSource as IEnumerable;
                   List<string> lstFile = new List<string>();
                   
                   foreach (var row in list)
                   {  
                       bool IsChecked = (bool)((CheckBox)dgloss.Columns[0].GetCellContent(row)).IsChecked;
                      
                       if (IsChecked)
                       {
                          string id = ((TextBlock)grdLossCodelist.Columns[2].GetCellContent(row)).Text;
                           lstFile.Add(id);
        
    }
    }    
    }

[Vlad]

Hello,

 This forum is for Telerik RadGridView. Maybe it will be better to post your questions related to Microsoft DataGrid to official Silverlight forums.

Greetings,
Vlad
the Telerik team