How can I call IValueConverter by user request? [XamDataGrid record index]

Question

I want to add record index like MS Excel in my XamDataGrid control. I use for this trick with IValueConverter. I define some template for displaying record indexes width this XAML-code:

<local:RowNumberConverter x:Key="rowNumberConverter" />

    <Style TargetType="{x:Type igDP:RecordSelector}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type igDP:RecordSelector}">
                    <TextBlock>
                            <TextBlock.Text>
                                <MultiBinding Converter="{StaticResource rowNumberConverter}">
                                    <Binding />
                                    <Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type igDP:XamDataGrid}}"/>
                                </MultiBinding>
                            </TextBlock.Text>
                    </TextBlock>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

RowNumberConverter defined as:

class RowNumberConverter : IMultiValueConverter {
      #region IMultiValueConverter Members

      public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture) {

         //get the grid and the item
         Object item = values[0];
         XamDataGrid grid = values[1] as XamDataGrid;

         int index = grid.RecordManager.Unsorted.IndexOf(((DataRecord)item));

         return index.ToString();
      }

      public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture) {
         throw new NotImplementedException();
      }

      #endregion
   }

This works perfectly when I add records in my XamDataGrid instance, but when I sort data by any field in my datagrid, record indexes also sorts (value converter does not calling when I press sort button). Maybe I can call it manually?

Thanks for any advices and sorry for my bad english.

Answer 1

I found solution with help of Infragistics support. It's combines several methods. So...

Write MultiValueConverter:

public class RowNumberConverter : IMultiValueConverter {

   #region IMultiValueConverter Members

   public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
   {
       if (values != null && values[0] != null)
       {
           Record r = values[0] as Record;
           return (r.VisibleIndex + 1).ToString();
       }
       else
           return null;
   }

   public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
   {
       throw new NotImplementedException();
   }
   #endregion

}

Register DepencyProperty:

public static readonly DependencyProperty DummyValueProperty =

      DependencyProperty.Register("DummyValue", typeof(int), typeof(XamRibbonWindow), new UIPropertyMetadata(0));

        public int DummyValue
        {
            get { return (int)GetValue(DummyValueProperty); }
            set { SetValue(DummyValueProperty, value); }
        }

Write style:

<Style TargetType="{x:Type igDP:RecordSelector}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type igDP:RecordSelector}">
                    <Border BorderBrush="#FFD4D4D4" BorderThickness="0,1.5,1.5,0" Background="#FFF1F1F1">
                        <TextBlock HorizontalAlignment="Center" Margin="0" TextWrapping="Wrap" VerticalAlignment="Center" FontSize="{Binding Path=FontSize, RelativeSource={RelativeSource AncestorType={x:Type igDP:XamDataGrid}}}">
                                <TextBlock.Text>
                                    <MultiBinding Converter="{StaticResource ResourceKey=rowNumberConverter}">
                                        <Binding />
                                        <Binding Path="DummyValue" RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type Window}}"/>
                                    </MultiBinding>
                                </TextBlock.Text>
                        </TextBlock>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Setter Property="MinWidth" Value="50"/>
    </Style>

Add event handlers for sorting event, delete event etc. with this code:

this.DummyValue++;

Thats all. Good luck :).

Answer 2

Value conversion happens when the properties are accessed (get/set) via DataBinding. You're sorting is not triggering this and I don't suspect you want it to since your sort probably does not work on the original collection and you'd probably get the items with the wrong row index on them again. I don't know of anyway, other than explicitly triggering a binding refresh, of getting the ValueConverter implementation to work.

Check this MSDN article for information on explicitly calling the UpdateSource method. I don't know if this will solve your problem unless you sort on the original object collection with LINQ.