public static T?FindParent <T>(this DependencyObject child)
where T : DependencyObject
{
DependencyObject parentObject = VisualTreeHelper.GetParent(child);
if (parentObject == null)
{
return(null);
}
T?parent = parentObject as T;
if (parent != null)
{
return(parent);
}
else
{
return(parentObject.FindParent <T>());
}
}
private static void OnFocusOnLoadChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var parentTreeView = d.FindParent<TreeListView>();
if (parentTreeView == null || !parentTreeView.IsFocusOnLoadEnabled) return;
var frameworkElement = d as FrameworkElement;
if (frameworkElement != null)
{
if (frameworkElement.IsLoaded)
{
Keyboard.Focus(frameworkElement);
}
else
{
frameworkElement.Loaded += FrameworkElement_Loaded;
}
}
}
static DependencyObject FindDragLeaveCommandHolder( DependencyObject originalSource )
{
var element = originalSource.FindParent<DependencyObject>( t =>
{
return DragDropManager.GetOnDragLeaveCommand( t ) != null;
} );
return element;
}
/// <summary>
/// Finds the WPF element where the DropTarget property has been defined.
/// </summary>
/// <param name="originalSource">
/// The original source where the Drop,
/// or DragOver, operation is happening.
/// </param>
/// <returns>
/// The element that holds the DropTarget,
/// or null if none can be found.
/// </returns>
static DependencyObject FindDropTargetContainer( DependencyObject originalSource )
{
var element = originalSource.FindParent<DependencyObject>( t =>
{
return DragDropManager.GetDropTarget( t ) != null;
} );
return element;
}
