[Solved] [URGENT] Need to change the DataTemplate but get an exception

[Michele]

Hello,
I'm creating a gridview dinamically, I've defined in the App.Resource a DataTemplate as :

<DataTemplate x:Name="hyperLinkTemplate">

<ContentPresenter>

<HyperlinkButton x:Name="hlClick" Content="{Binding}" Click="hlClick_Click"></HyperlinkButton>

</ContentPresenter>
</DataTemplate>

In the codebehind of the XAML where I add the column I do :

foreach (Colonna colonna in header)
               {
                   GridViewDataColumn c = new GridViewDataColumn();

                   c.Header = colonna.N;
                   string columName = string.Format("Colonne[{0}].V", count++);
                   c.DataMemberBinding = new System.Windows.Data.Binding(columName);
                   c.UniqueName = columName;
                   c.DataType = Type.GetType(colonna.T);

                   c.CellTemplateSelector = App.Current.Resources["utilityCellTemplateSelector"] as DataTemplateSelector;

                   if (c.DataType == typeof(DateTime))
                   {
                       c.DataFormatString = "{0:dd/MM/yyyy}";
                       c.SortMemberPath = columName;
                       c.SortingState = SortingState.Ascending;
                   }
                   gvContent.Columns.Add(c);
               }

The UtilityCellTemplateSelector is defined as :

public class UtilityCellTemplateSelector : DataTemplateSelector
  {
      public override System.Windows.DataTemplate SelectTemplate(object item, System.Windows.DependencyObject container)
      {
          var cell = container as GridViewCell;

          if (cell != null && cell.DataColumn is GridViewDataColumn)
          {
              var column = cell.DataColumn as GridViewDataColumn;

              string memberPath = column.DataMemberBinding.Path.Path;

              System.Windows.DataTemplate dataTemplate = App.Current.Resources["hyperLinkTemplate"] as System.Windows.DataTemplate;

             var ar = dataTemplate.FindChildByType<HyperlinkButton>();
              return dataTemplate;
          }

          return null;
      }
  }

when I pass the var ar .... I got :  Reference is not a valid visual DependencyObject.

I need to access to the hyperlinkbutton since I need to specify the parameters to open the detail...
Thanks

Paolo

[Nedyalko Nikolov]

Hi Paolo,

You cannot call FindChildByType<T>() method for a DataTemplate even that DataTemplate is a DependencyObject, because DataTemplate indeed is not visual. You have to call this method on the FrameworkElement which is a result of DataTemplate.LoadContent() method.
I hope this helps.

Greetings,
Nedyalko Nikolov
the Telerik team