Ios Swift:SLKTextViewController'；不查看“左”按钮

我正在使用SLKTextViewController构建带有两个按钮的聊天dockview

我想要带

UIPopOverController

的左键拍照等等

class Message: SLKTextViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
          self.textView.placeholder = "Message"
        self.textView.placeholderColor = UIColor.lightGrayColor()
        self.leftButton.setImage(UIImage(named: "icn_upload"), forState: UIControlState.Normal)
        self.leftButton.tintColor = UIColor.grayColor()
        self.rightButton.setTitle("Send", forState: UIControlState.Normal)
        self.textInputbar.autoHideRightButton = true
        self.textInputbar.maxCharCount = 31
        self.textInputbar.counterStyle = SLKCounterStyle.Split
        self.typingIndicatorView.canResignByTouch = true
        self.bounces = true
        self.shakeToClearEnabled = true
        self.keyboardPanningEnabled = true
        self.inverted = false

我加上这个是为了让它看起来像，但它没有

        self.leftButton.hidden = false
    }

---

如果您需要显示左键，只需在其上加上首字母即可

self.leftButton.addTarget(self, action: Selector("cameraPressed"), 
    forControlEvents: UIControlEvents.TouchUpInside)
self.leftButton.setImage(UIImage.init(named:"CameraIcon"), forState: UIControlState.Normal)

然后可以在CameraPressed函数中添加UIPopOverController。（不过我更喜欢UIAlertController样式）