XAML components ("controls" in MS terminology) contain both declarative markup and code. And it's flexible because the visual presentation can be completely overriden by the component's consumer without altering behavior, and your code can be either C# or C++.
What does dependency injection have to do with anything? There's nothing stopping you from using global variables or an event bus or something like Redux in a XAML app.
What does dependency injection have to do with anything? There's nothing stopping you from using global variables or an event bus or something like Redux in a XAML app.