How to make your WPF automatically fill up the hosting form

I was puzzled about the fact that in WPF controls, there's nothing called Anchor. I was used to use Anchor to make the height and width to link to the size of the form with WinForm, but they are not there for WPF controls.

Finally I realized that the property of Height and Width for a WPF control can be set to "Auto". Doing so makes the control to automatically resize to match the form size. Pretty awesome.