How to set the left margin of rightview

Solution:

add a bottom view

 

let countdownBtn = UIButton.init(frame: CGRectMake(-10, 0, 62, 28))
let rightBackView = UIView.init(frame:CGRectMake(0, 0, 72, 28))
rightBackView.addSubview(countdownBtn)
textFeild.rightView = rightBackView