Hi,

I'm trying to set the HeaderStyle in codebehind based on a check of the datarow.

I do this in the CellControlAttached event:

if (e.Cell.Column.Tag != null)
 {
      currentYear = (DateTime)e.Cell.Column.Tag;
      DateTime checkDate = currentYear.AddDays(-7);
       if (currentYear.Year != checkDate.Year)
        {
               e.Cell.Column.HeaderStyle = this.Resources["NewYear"] as Style;
                                
         }}

The style is defined as followed:

xmlns:igGridDet="clr-namespace:Infragistics.Silverlight.Controls.Primitives;assembly=Infragistics.Silverlight.XamWebGrid.v9.2"

 <Style x:Key="NewYear" TargetType="igGridDet:HeaderCellControl">
            <Setter Property="Background" Value="Yellow"></Setter>
        </Style>

However, when I run this code I get: Object reference not set to an instance of an object