ios - How to add a floating button in UITableViewController which does not scroll when table is scrolled? -

currently there uitableviewcontoller many sections , rows.

what best way add button floats on top of table view. button should not scroll when cells scrolled.

currently have following code , button still scrolls:

override func viewdidload() {     super.viewdidload()     self.view.addsubview(viewforfooter) } 

the viewforfooter separate view contains button needs floating. thank you. appreciated.

here option if don't want use uiview subviews...

override func viewdidload() {     super.viewdidload()      if let app = uiapplication.shared.delegate as? appdelegate, let window = app.window {         print("adding view-with-button keywindow")         window.addsubview(viewforfooter)         viewforfooter.topanchor.constraint(equalto: window.topanchor, constant: 120).isactive = true         viewforfooter.leftanchor.constraint(equalto: window.leftanchor, constant: 40).isactive = true     }      // other stuff... } 

this add view subview of "keywindow" @ 40,120, , "hover" there while scroll table. assuming viewforfooter instantiated , have necessary constraints set correctly.