DoubleClick Trigger for DataGrid in Silverlight and C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Interactivity;
using System.Windows.Media;
using System.Windows.Threading;namespace Projects.Infrastructure.Triggers
{
public class DataGridMouseDoubleClickTrigger : TriggerBase
{
private readonly DispatcherTimer timer;
private MouseButtonEventHandler _datagridMouseLeftButtonDownHandler;
private DateTime _lastMouseDownDateTime = DateTime.Now;
private bool _hasFirstMouseDownOccured = false;
private Point _firstMouseDownPosition;

protected override void OnAttached()
{
if (AssociatedObject != null)
{
_datagridMouseLeftButtonDownHandler = new MouseButtonEventHandler(OnGridViewMouseLeftButtonDown);
AssociatedObject.AddHandler(UIElement.MouseLeftButtonDownEvent, _gridViewMouseLeftButtonDownHandler, true);
}
}

protected override void OnDetaching()
{

if (AssociatedObject != null && _datagridMouseLeftButtonDownHandler != null)
{
AssociatedObject.RemoveHandler(UIElement.MouseLeftButtonDownEvent, _datagridMouseLeftButtonDownHandler);
}
}

private void OnTimerTick(object sender, EventArgs e)
{
timer.Stop();
}

private static bool IsGridViewRow(DataGrid GridView, Point mousePosition, ref object rowDataContext)
{
GeneralTransform gt = GridView.TransformToVisual(Application.Current.RootVisual);
Point mousePositionOffset = gt.Transform(mousePosition);

IEnumerable hitElements = VisualTreeHelper.FindElementsInHostCoordinates(mousePositionOffset, GridView);

var gridViewRow = hitElements.OfType().FirstOrDefault();

if (gridViewRow != null)
{
rowDataContext = gridViewRow.DataContext;
}

return gridViewRow != null;
}

private void OnGridViewMouseLeftButtonDown(object sender, MouseButtonEventArgs args)
{
DateTime currentMouseDownDateTime = DateTime.Now;
TimeSpan timeSpanBetweenButtonDowns = currentMouseDownDateTime – _lastMouseDownDateTime;

if (timeSpanBetweenButtonDowns.TotalMilliseconds > 300 || _hasFirstMouseDownOccured == false)
{
_firstMouseDownPosition = args.GetPosition(AssociatedObject);
_hasFirstMouseDownOccured = true;
_lastMouseDownDateTime = DateTime.Now;
}
else
{
Point currentMousePosition = args.GetPosition(AssociatedObject);

object rowDataContext = null;

if ((Math.Abs(_firstMouseDownPosition.X – currentMousePosition.X) < 4 && Math.Abs(_firstMouseDownPosition.Y – currentMousePosition.Y) < 4)
&& IsGridViewRow(AssociatedObject, currentMousePosition, ref rowDataContext)
)
{
InvokeActions(rowDataContext);
}
_hasFirstMouseDownOccured = false;
}
}

}

}

xmlns:Triggers=”clr-namespace:Project.Client.Infrastructure.Triggers;assembly= Project.Client.Infrastructure”
xmlns:i=”clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity”

<sdk:DataGrid HorizontalAlignment=”Stretch” Margin=”5″ MaxWidth=”475″ Grid.Column=”6″ Grid.Row=”3″
ItemsSource=”{Binding GridDataSource}”
VerticalAlignment=”Stretch” CanUserResizeColumns=”False”
MinHeight=”120″ AutoGenerateColumns=”False”
SelectedItem=”{Binding SelectedRecord, Mode=TwoWay}”>
<sdk:DataGrid.Columns >
<sdk:DataGridTextColumn Binding=”{Binding ItemName, Mode=TwoWay}” Header=”Item Name” Width=”*” IsReadOnly=”True” />
</sdk:DataGrid.Columns>
<i:Interaction.Triggers>
<Triggers:DataGridMouseDoubleClickTrigger>
<Triggers:ExecuteCommandAction Command=”{Binding OpenItemCommand}” />
</Triggers:DataGridMouseDoubleClickTrigger>
</i:Interaction.Triggers>
</sdk:DataGrid>

public class DataGridViewModel
{
public ICommand OpenItemCommand { get; set; }
public DataGridViewModel()
{
OpenItemCommand = new DelegateCommandprivate void ExecuteOpenItemCommand(object obj)
{
MessageBox.Show(“Double Click Trigger is fired to open current item.”);
}
}