The graphics editor for a XAML file is not yet supported in Visual Studio 2017.
That is, you cannot drag elements with the mouse.
In a XAML file, you need to write the text manually. Launch the project and see how the elements are placed.

If you create elements from C# code, then the readability of the code decreases and the complexity of development increases.
But the code compiles and becomes a little more performant.

XAML is considered to be more readable.