public static T FindParent <T>(DependencyObject child) where T : DependencyObject
{
if (!(child is Visual))
{
return(null);
}
DependencyObject parent = VisualTreeHelper.GetParent(child) as DependencyObject;
if (parent == null)
{
return(null);
}
if (parent is T)
{
return(parent as T);
}
return(VisualTreeExtensions.FindParent <T>(parent));
}
public static T FindParentByName <T>(DependencyObject child, string name) where T : DependencyObject
{
DependencyObject parent = VisualTreeHelper.GetParent(child) as DependencyObject;
if (parent == null)
{
return(null);
}
FrameworkElement fe = parent as FrameworkElement;
if (fe != null)
{
if (fe is T && fe.Name.CompareTo(name) == 0)
{
return(parent as T);
}
}
return(VisualTreeExtensions.FindParent <T>(parent));
}
// A common way to implement an adorner's rendering behavior is to override the OnRender
// method, which is called by the layout system as part of a rendering pass.
protected override void OnRender(DrawingContext drawingContext)
{
Rect adornedElementRect = new Rect(this.AdornedElement.DesiredSize);
// Some arbitrary drawing implements.
SolidColorBrush renderBrush = new SolidColorBrush(Colors.White);
//renderBrush.Opacity = 0.2;
double renderRadius = 5.0;
// Draw a circle at each corner.
Viewbox parentViewbox = VisualTreeExtensions.FindParent <Viewbox>(this.AdornedElement);
double factor = parentViewbox.Child.RenderSize.Width / parentViewbox.RenderSize.Width;
renderRadius *= factor;
Pen renderPen = new Pen(Brushes.Black, 1.5 * factor);
drawingContext.DrawEllipse(renderBrush, renderPen, adornedElementRect.TopLeft, renderRadius, renderRadius);
drawingContext.DrawEllipse(renderBrush, renderPen, adornedElementRect.TopRight, renderRadius, renderRadius);
drawingContext.DrawEllipse(renderBrush, renderPen, adornedElementRect.BottomLeft, renderRadius, renderRadius);
drawingContext.DrawEllipse(renderBrush, renderPen, adornedElementRect.BottomRight, renderRadius, renderRadius);
}