重写UITextField子类的drawRect方法

class UITextFieldX: UITextField {    override func drawRect(rect: CGRect) {        super.drawRect(rect)                 // 键盘完成按钮        var toolBar = UIToolbar(frame: CGRectMake(0, 0, screenSize().width, 30))        toolBar.barStyle = UIBarStyle.Default                 var btnFished = UIButton(frame: CGRectMake(0, 0, 50, 25))        btnFished.setTitleColor(RGB(4, 170, 174), forState: UIControlState.Normal)        btnFished.setTitleColor(UIColor.grayColor(), forState: UIControlState.Highlighted)        btnFished.setTitle("完成", forState: UIControlState.Normal)        btnFished.addTarget(self, action: "finishTapped:", forControlEvents: UIControlEvents.TouchUpInside)        var item2 = UIBarButtonItem(customView: btnFished)                 var space = UIView(frame: CGRectMake(0, 0, screenSize().width - btnFished.frame.width - 30, 25))        var item = UIBarButtonItem(customView: space)                 toolBar.setItems([item,item2], animated: true)                 self.inputAccessoryView = toolBar    }         func finishTapped(sender:UIButton){        self.resignFirstResponder()    } } func screenSize() -> CGSize{    return UIScreen.mainScreen().bounds.size} func RGB (r:CGFloat, g:CGFloat, b:CGFloat) -> UIColor {    return UIColor(red: r/255.0, green: g/255.0, blue: b/255.0, alpha: 1)}

效果如下