How to Reuse Existing Layouting Code for new Panel Class?
问题 tl;dr: I want to reuse the existing layouting logic of a pre-defined WPF panel for a custom WPF panel class. This question contains four different attempts to solve this, each with different downsides and thus a different point of failure. Also, a small test case can be found further down. The question is: How do I properly achieve this goal of defining my custom panel while internally reusing the layouting logic of another panel, without running into the problems described in my attempts to