问题
Ok, I know that FrameworkElement, which is a direct subclass of UIElement, has a Parent property, but Panels have children of type UIElement, not FrameworkElement (Children is of type UIElementCollection) which seems it would mean you can add UIElements directly to a Panel.
That said, if you have a UIElement and want to see if it has a parent that's a panel, the only way I know how to test this is with the VisualTreeHelper, but that's the visual tree, not the logical tree. (At least we know a Panel doesn't have a template so maybe that's the way, but still...)
So asides from the VisualTreeHelper, does anyone know how to know which panel is the parent of a UIElement? (...and have any thoughts why they didn't just define a Parent property there instead of on FrameworkElement?)
Thanks!
回答1:
Well, if you need to find a logical parent you can just use LogicalTreeHelper in the same manner as VisualTreeHelper.
As for "...and have any thoughts why they didn't just define a Parent property there instead of on FrameworkElement?". Basically, the notion of "Logical Tree" is introduced on the FrameworkElement level. See http://msdn.microsoft.com/en-us/library/system.windows.frameworkelement.aspx (see Remarks) for details of what FrameworkElement adds to UIElement. Here is what it says about Logical Trees:
The logical tree: The general WPF programming model is often expressed in terms of being a tree of elements. Support for expressing the tree of elements as a logical tree, and accompanying support for defining that tree in markup is implemented at the FrameworkElement level. Note however that FrameworkElement deliberately does not define a content model, and leaves that responsibility to derived classes. For more information, see Trees in WPF.
来源：https://stackoverflow.com/questions/5000228/how-can-you-get-the-parent-of-a-uielement