protected internal virtual void RemoveVisualChild(Visual child)
{
if (child == null)
return;
if (child._Parent != this)
throw new ArgumentException("Not child parent.");
child._Parent = null;
}
protected internal virtual void AddVisualChild(Visual child)
{
if (child == null)
return;
if (child._Parent != null)
throw new ArgumentException("Child has parent.");
child._Parent = this;
}