Xcode 如何使用UIBarButtonSystemItem更改UIBarButtonItem标识符？（Swift）

我想用代码将一个uibarbuttonite的标识符从“Play”改为“Pause”。我该怎么做

谢谢你（打开一个新按钮

//change to play
let button = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Play, target: self, action: "someAction")
navigationBar.topItem.leftBarButtonItem = button

//change to pause
let button = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Pause, target: self, action: "someOtherAction")
navigationBar.topItem.leftBarButtonItem = button

2） 只需更改文本：

navigationBar.topItem?.leftBarButtonItem?.title = "AnyText"

如果访问导航栏时遇到问题，最好只设置一些标记（我喜欢对特定视图使用负标记*以确保两个视图*没有相同的标记）。 然后你可以这样做：

let navigationBar = (self.view.viewWithTag(-1) as UINavigationBar)
navigationBar.topItem?.leftBarButtonItem?.title = "AnyText"

---

对于工具栏项，以下是示例代码

var player:AVAudioPlayer = AVAudioPlayer()

@IBOutlet var toolbar: UIToolbar!
@IBOutlet var playPauseButton: UIBarButtonItem!

@IBAction func playPause(sender: AnyObject) {

    if player.playing {

        player.pause()

        playPauseButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Play, target: self, action: "playPause:")

        toolbar.items![0] = playPauseButton //apply for first toolbar item

    } else {

        player.play()

        playPauseButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Pause, target: self, action: "playPause:")

        toolbar.items![0] = playPauseButton //apply for first toolbar item


    }

}

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我看了几个线程，这是唯一的答案，实际上做到了我所寻找的。我唯一的问题是，它将我的工具栏项移到最左边，而我将其居中。如果按钮以灵活的空格键居中，或者不是第一个按钮，只需按如下方式更改索引：

---

toolbar.items！[1] =playPauseButton//apply for second toolbar item

此代码经过测试，可用于Swift 2

@IBOutlet weak var navigationBar: UINavigationBar!

//playToPause()
@IBAction func playButton(sender: UIBarButtonItem) {

    let newBarButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Pause, target: self, action: "pauseButton:")
    navigationBar.topItem?.rightBarButtonItem = newBarButton
}

// pauseToPlay()
@IBAction func pauseButton(sender: UIBarButtonItem){

    let pauseBtnItem = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Play, target: self, action: "playButton:")
    navigationBar.topItem!.rightBarButtonItem = pauseBtnItem
}

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我使用此代码切换编辑模式

@IBAction func editMode(sender: UIBarButtonItem) {
    self.setEditing(!self.isEditing, animated: true)

    let newButton = UIBarButtonItem(barButtonSystemItem: (self.isEditing) ? .done : .edit, target: self, action: #selector(editMode(sender:)))
    self.navigationItem.setLeftBarButton(newButton, animated: true)
}

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可能是ho michar vu ahmed的复制品？？不，不是。我问的是swift。如果我们已经将项目注入工具栏，则不需要playPauseButton出口引用。