Xamarin forms: Absolute Layout Listview Scrolling is not working

I have a listview inside an AbsoluteLayout and my problem is listview scrolling is not working.

Please see the below screenshot of code:

And the output screen is like below:

I have added AbsoluteLayout for putting the Imagebutton on top of Listview. If I cover the AbsoluteLayout with a scrollview, then scrolling works, but the Imagebutton is not showing on top of Listview. It is placed on the bottom after listview items.

Please suggest a solution for this, Thanks.