Question

导航栏上有一个Save（系统项）BarButtonItem当用户点击此UIActivityIndicatorView按钮时，我在导航栏上显示Save我想要在某些条件下再次出现这个Barbutton（保存）。首先我认为问题是我在customView上添加了一个指示器，所以我不需要隐藏barbutton.It在启动指示器后会自动隐藏。但现在不知道如何再次显示保存按钮。或如何从customView

中删除指标

这就是我正在做的事情

 @IBOutlet weak var saveButtonOutlet: UIBarButtonItem!
 var activityIndicatorView:UIActivityIndicatorView!
func showActivityIndicator() {

         activityIndicatorView = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.White)
        activityIndicatorView.frame = CGRectMake(0, 0, 14, 14)
        activityIndicatorView.color = UIColor().blueColorIOS()
        activityIndicatorView.startAnimating()

        let barButtonItem = UIBarButtonItem(customView:  activityIndicatorView)
        self.navigationItem.rightBarButtonItem = barButtonItem
      }


   @IBAction func saveButtonClicked(sender: UIBarButtonItem) {

        showActivityIndicator()

      ServerRequest.postToServer(url, params: params){
            result, error in
            if let result = result {
                let code =  result["code"] as? Int
                print(result)
                if (code==200){

                    dispatch_after(DISPATCH_TIME_NOW, dispatch_get_main_queue(), { ()->() in

                        self.activityIndicatorView.hidden = true
                        self.activityIndicatorView.hidesWhenStopped = true
                        //here want to show again "saveButtonOutlet" 

                                       })


                }

            }
        }



    }


   }

Answer 1

我认为您需要做的就是将self.navigationItem.rightBarButtonItem重置为saveButtonOutlet。现在为我工作。

Answer 2

所以一种方法是再次创建“保存”按钮，然后再次设置rightBarButtonItem：

...
self.activityIndicatorView.hidden = true
self.activityIndicatorView.hidesWhenStopped = true
let barButtonItem = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Save, target: self, action: "saveButtonClicked:")
self.navigationItem.rightBarButtonItem = barButtonItem

我还会将self.activityIndicatorView.hidden = true替换为self.activityIndicatorView.stopAnimating()以正确使用hidesWhenStopped属性。

在UIActivity Indicator在导航栏上停止后，UIBarbutton“保存”不再出现

2 个答案: