ios - 更改 Swift 中的导航栏按钮图标

Question

当我点击按钮图标时，我正在尝试将“播放”按钮图标更改为“暂停”。但我的代码不起作用。

这是我的@IBAction 代码。

@IBAction func playTimer(sender: AnyObject) {

    if buttonSwitch == 0 {
        timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("result"), userInfo: nil, repeats: true)
        buttonSwitch = 1

        self.navigationItem.setLeftBarButtonItem(UIBarButtonItem(barButtonSystemItem: .Pause, target: self, action: "setAlarm"), animated: true)

        println("2")

    } else {
        timer.invalidate()
        buttonSwitch = 0
    }

}

我已经尝试了一切，但什么也没发生。没有错误，图标也没有改变。

Answer 1

//oh sorry! previously i had given Objective c code..., 

 var imageCheckUI:UIImage = UIImage(named: "checkmark-25.png")!
        var rectCheckFram : CGRect = CGRectMake(-10, 0, 20, 20)
        var BtnCheckUI : UIButton = UIButton(frame: rectCheckFram)
        BtnCheckUI .setBackgroundImage(imageCheckUI, forState: UIControlState.Normal)
        BtnCheckUI.addTarget(self, action: "Correctdata", forControlEvents:.TouchUpInside)


        imageCheckUI = UIImage(named: "appbar.close.png")!
        rectCheckFram  = CGRectMake(-10, 0, 30, 30)
        var BtnCloseUI : UIButton = UIButton(frame: rectCheckFram)
        BtnCloseUI .setBackgroundImage(imageCheckUI, forState: UIControlState.Normal)
        BtnCloseUI.addTarget(self, action: "close", forControlEvents:.TouchUpInside)
        let barbtncheck: UIBarButtonItem = UIBarButtonItem(customView: BtnCheckUI)
        var  barbtnRIght :UIBarButtonItem = UIBarButtonItem(customView: BtnCloseUI)
        let array:NSArray = NSArray(objects: barbtncheck,barbtnRIght)
        self.navigationItem.setRightBarButtonItems(array, animated: true)