# GroupHeaderTap Command

The `GroupHeaderTap` command handles the tap gesture over a group header. The default implementation will toggle (expand or collapse) the underlying `IDataGroup` implementation.

## Execution Parameter

The execution parameter is of type `GroupHeaderContext` and exposes the following properties:

* `Level`—Gets the zero-based level (depth) of the group within the current data `View`.
* `Descriptor`—Gets the `GroupDescriptorBase` instance that defines the grouping level for the group header that has been tapped.
* `IDataGroup`—Gets the `IDataGroup` implementation that represents the data group abstraction.
* `IsExpanded`—Gets or sets the current `IsExpanded` state of the associated data group.

## Custom GroupHeaderTap Command

The following examples show how to create a class that inherits from the `DataGridCommand` and add it to the `Commands` collection.

#### **Create a Custom GroupHeaderTap Command**

```C#
public class CustomGroupHeaderTapCommand : DataGridCommand
{
	public CustomGroupHeaderTapCommand()
	{
		this.Id = CommandId.GroupHeaderTap;
	}

	public override bool CanExecute(object parameter)
	{
		var context = parameter as GroupHeaderContext;
		// put your custom logic here
		return true;
	}

	public override void Execute(object parameter)
	{
		var context = parameter as GroupHeaderContext;
		// put your custom logic here     

		this.Owner.CommandService.ExecuteDefaultCommand(CommandId.GroupHeaderTap, context);          
	}
}
```

#### **Add the Custom Command to the Commands Collection**

```XAML
<Grid xmlns:grid="using:Telerik.UI.Xaml.Controls.Grid">
	<grid:RadDataGrid Width="600" Height="460" x:Name="grid">
		<grid:RadDataGrid.Commands>
			<local:CustomGroupHeaderTapCommand/>
		</grid:RadDataGrid.Commands>
	</grid:RadDataGrid>
</Grid>
```

## See Also

* [ColumnHeaderTap](https://www.telerik.com/winui/documentation/controls/raddatagrid/commands/datagrid-columnheadertapcommand)
* [CellTap](https://www.telerik.com/winui/documentation/controls/raddatagrid/commands/datagrid-celltapcommand)
* [CellDoubleTap](https://www.telerik.com/winui/documentation/controls/raddatagrid/commands/datagrid-celldoubletappedcommand)
* [FilterButtonTap](https://www.telerik.com/winui/documentation/controls/raddatagrid/commands/datagrid-filterbuttontapcommand)