uibutton

let button = UIButton(type: .Custom)
button.frame = CGRectMake(100, 100, 100, 50)
button.backgroundColor = UIColor.greenColor()
button.setTitle("Button", forState: UIControlState.Normal)

button.addTarget(self, action: #selector(buttonPressed(_:)), forControlEvents: UIControlEvents.TouchUpInside)
self.addSubview(button)