how add button and resize and drag it in app xamarin android

You need to implement OnTouchListener. Listen OnTouch events for the button and update the Layout of the button accordingly in Move Event .

Refer here for more details

https://developer.xamarin.com/recipes/android/other_ux/gestures/detect_a_touch/

http://pumpingco.de/adding-drag-and-drop-to-your-android-application-with-xamarin/

I believe this will help you ,if any please reply same

Thanks

Suthahar.J