如何在xcode中单击它时更改按钮标识符

I'm new to Xcode and I'm using Swift to program a stopwatch. I have three functionalities - Play, Stop & Pause. Play and Pause should be the same button and alternate between states. How do I accomplish this in code?

我是Xcode的新手,我正在使用Swift来编写秒表。我有三个功能 - 播放,停止和暂停。播放和暂停应该是相同的按钮,并在状态之间交替。我如何在代码中完成此操作?

2 个解决方案

#1

You can user the property selected of button like this :

您可以像这样使用所选按钮的属性:

setup your button states in viewDidLoad:

在viewDidLoad中设置按钮状态:

startButton.setTitle("Stop", forState: UIControlState.Selected)
startButton.setTitle("start", forState: UIControlState.Normal)

Now you can change the button states when it's tapped:

现在,您可以在点按时更改按钮状态:

@IBAction func startPauseAction(sender: UIButton) {
   sender.selected = !sender.selected // action changed the selected 
   if sender.selected {
     play()
   } else {
     pause()
 }
}

#2

Using an enum for button state

使用枚举按钮状态

enum ButtonType {
    case Stop
    case Play
    case Pause
}
var btnType: ButtonType = .Stop

@IBOutlet weak var actionBtn: UIButton!
@IBAction func buttonClicked(sender: UIButton)  {
switch (self.btnType) {
    case .Stop:
        self.btnType = .Play
        // TODO: Change button image/title for current state
        break
    case .Play:
        self.btnType = .Pause
        // TODO:
        break

    case .Pause:
        // TODO:
        break
    }
}

#1