How to apply cell and edit template based on row index in WPF TreeGrid?

Typically, in a template selector, the cell and edit templates are loaded based on the value of the underlying data object. With the customization below, we can load templates based on the row index of the SfTreeGrid. To achieve this, we’ve defined a static property for the SfTreeGrid in both selector classes and assigned the TreeGrid instance within the MainWindow class.

XAML code:

<Window.Resources>
   <local:CustomCellTemplateSelector x:Key="cellTemplateSelector" />
   <local:CustomEditTemplateSelector x:Key="editTemplateSelector"/>

   <DataTemplate x:Key="ComboBoxCellTemplate">
       <Grid>
           <syncfusion:ComboBoxAdv BorderBrush="Transparent" Background="Transparent" Grid.Column="1" 
                                   SelectedItem="{Binding SelectedComboItem}"
           ItemsSource="{Binding ComboBoxItems}" syncfusion:VisualContainer.WantsMouseInput="False"
           syncfusion:FocusManagerHelper.FocusedElement="True" />
       </Grid>
   </DataTemplate>

   <DataTemplate x:Key="TextBlockCellTemplate">
       <TextBlock VerticalAlignment="Center"
   Text="{Binding Path=FirstName}"/>
   </DataTemplate>
   
   <DataTemplate x:Key="ComboBoxEditTemplate">
       <Grid>
           <syncfusion:ComboBoxAdv BorderBrush="Transparent" Background="Transparent" Grid.Column="1" 
                                   SelectedItem="{Binding SelectedComboItem}"
                           ItemsSource="{Binding ComboBoxItems}" syncfusion:VisualContainer.WantsMouseInput="False"
                           syncfusion:FocusManagerHelper.FocusedElement="True" />
       </Grid>
   </DataTemplate>

   <DataTemplate x:Key="TextBoxEditTemplate">
       <TextBox Height="20"
   VerticalAlignment="Center" syncfusion:FocusManagerHelper.FocusedElement="True"
   Text="{Binding Path=FirstName}" />
   </DataTemplate>
</Window.Resources>

C# code:

public MainWindow()
{
   InitializeComponent();
   CustomCellTemplateSelector.SfTreeGridCell = this.treeGrid;
   CustomEditTemplateSelector.SfTreeGridEdit = this.treeGrid;
}

public class CustomEditTemplateSelector : DataTemplateSelector
{
   public static SfTreeGrid SfTreeGridEdit { get; set; }
   public override System.Windows.DataTemplate SelectTemplate(object item, System.Windows.DependencyObject container)
   {

       if (item == null)
           return null;
       var data = item as EmployeeInfo;
       var recordRowIndex = (SfTreeGridEdit.DataContext as ViewModel).Employees.IndexOf(data);
       var rowIndex = SfTreeGridEdit.ResolveToRowIndex(recordRowIndex);
       if (rowIndex == 1 || rowIndex == 3)
           return Application.Current.MainWindow.FindResource("ComboBoxEditTemplate") as DataTemplate;

       else
           return Application.Current.MainWindow.FindResource("TextBoxEditTemplate") as DataTemplate;
   }
}

public class CustomCellTemplateSelector : DataTemplateSelector
{
   public static SfTreeGrid SfTreeGridCell { get; set; }
   public override System.Windows.DataTemplate SelectTemplate(object item, System.Windows.DependencyObject container)
   {
       if (item == null)
           return null;
       var data = item as EmployeeInfo;
       var recordRowIndex = (SfTreeGridCell.DataContext as ViewModel).Employees.IndexOf(data);
       var rowIndex = SfTreeGridCell.ResolveToRowIndex(recordRowIndex);
       if (rowIndex == 1 || rowIndex == 3)
           return Application.Current.MainWindow.FindResource("ComboBoxCellTemplate") as DataTemplate;

       else
           return Application.Current.MainWindow.FindResource("TextBlockCellTemplate") as DataTemplate;
   }
}

Image reference:

View the sample in GitHub

Take a moment to peruse the WPF-SfTreeGrid Template Selector Documentation, to learn more about template selector with examples.

Conclusion

I hope you enjoyed learning about how to apply cell and edit template based on row index in WPF TreeGrid.

You can refer to our WPF TreeGrid feature tour page to know about its other groundbreaking feature representations. You can also explore our documentation to understand how to create and manipulate data.

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