Silverlight DataGrid: Make Right-click Select a Row
A slightly irking characteristic of many data grid libraries is that there seems to be a disconnect between expected usability in a grid, and the default behaviour of those same grids. I’ve found this to be a problem in all .NET grids that I’ve used including Infragistics and Microsoft’s WPF/Silverlight implementations.
For example, one thing I expect to be able to do is right-click on a grid’s row, and have it pull up a context menu with a list of actions to perform on it. Now that context menus have been added to Silverlight 4, half the battle is won, but you still can’t get the “correct” right-click behavior out of the box.
Here’s how to coax the grid to behave a bit more properly with VisualTreeHelper.
<!-- XAML -->
<UserControl x:Class="MyControl"
xmlns:grid="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data"
xmlns:toolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit">
<grid:DataGrid MouseRightButtonDown="_grid_MouseRightButtonDown">
<!-- Define a context menu for our grid here -->
<toolkit:ContextMenuService.ContextMenu>
<toolkit:ContextMenu>
<toolkit:MenuItem Header="Action!" />
</toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>
</grid:DataGrid>
</UserControl>
// Code-behind
private void _grid_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
IEnumerable<UIElement> elementsUnderMouse =
VisualTreeHelper
.FindElementsInHostCoordinates(e.GetPosition(null), this);
DataGridRow row =
elementsUnderMouse
.Where(uie => uie is DataGridRow)
.Cast<DataGridRow>()
.FirstOrDefault();
if (row != null)
_grid.SelectedItem = row.DataContext;
}
The code above uses VisualTreeHelper to find any UIElements under the mouse when the user performs a right-click. A set of UIElements is returned including grid rows and cells as well as a good number of other elements. We filter this set for an instance of DataGridRow, get is bound data item, then tell the grid to select that object.