How to stretch in width a WPF user control to its window?

Question

I have a Window with my user control and I would like to make usercontrol width equals window width. How to do that?

The user control is a horizontal menu and contains a

Answer 1

Is the Canvas crucial in your window? If not, try removing it and keep the Grid as the main panel. Canvas has no size unless specified, while a Grid normally takes up all available space. Inside the Canvas, the Grid will have no available space.