WPF

private void grid_MouseRightButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)        
{            
    MatrixElement elem = GetDependencyObjectFromVisualTree((DependencyObject)sender, typeof(MatrixElement)) as MatrixElement;
}

private static DependencyObject GetDependencyObjectFromVisualTree(DependencyObject startObject, Type type)
{
    // Iterate the visual tree to get the parent of this control
    DependencyObject parent = startObject;
    while (parent != null)
    {
        if (type.IsInstanceOfType(parent))
            break;
        else
            parent = VisualTreeHelper.GetParent(parent);
    }
    return parent;
}

if (e.OriginalSource is MatrixElement)
            {
                MatrixElement elemnt = e.OriginalSource as MatrixElement;
            }