ios - 在 swift 4 中添加带计时器的导航栏刷新按钮

Question

我正在尝试添加一个导航栏刷新按钮来更新来自 JSON 的 TableView 内容，此外，如果用户没有按下刷新按钮并更改，我希望我的 TableView 每 5 分钟自动更新一次按钮是一个事件指示器，让正在更新的用户在 TableView 更新数据时

我的刷新按钮 IBAction 代码:

@IBAction func refreshButton(_ sender: Any) {

    self.getCoinData()
    self.coinTableView.reloadData()
}

Answer 1

swift 4+

创建 Timer 并在网络服务完成时显示重新加载图标

class ViewController: UIViewController {

    var timer: Timer!
    var refreshBarButtonActivityIndicator: UIBarButtonItem!
    var refreshBarButton: UIBarButtonItem!
    override func viewDidLoad() {
        super.viewDidLoad()
        barItemSetUp()
    }
    func barItemSetUp() {
        ///SettingReloadButton
        let image = UIImage(named: "refresh-25")?.withRenderingMode(.alwaysOriginal)
        refreshBarButton = UIBarButtonItem(image: image, style: .plain, target: self, action: nil)
        ///Setting activity Indicator
        let activityIndicator: UIActivityIndicatorView = UIActivityIndicatorView.init(activityIndicatorStyle: .gray)
        refreshBarButtonActivityIndicator = UIBarButtonItem(customView: activityIndicator)
        activityIndicator.startAnimating()
        toogleIndicator()
    }
   deinit {    
     timer?.invalidate()
   }
    func toogleIndicator() {
        // 5 minutes = 300 seconds //write here 300
        timer = Timer.scheduledTimer(timeInterval: 3, target: self, selector: #selector(refreshNow), userInfo: nil, repeats: true)
    }

    @objc func refreshNow() {
        //here i am creating delay for sample purpose
        //here write your webservice code on completion of webservice change bar button item
        self.navigationItem.rightBarButtonItem = refreshBarButtonActivityIndicator
        DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 2) {
            self.navigationItem.rightBarButtonItem = self.refreshBarButton
        }
    }
}

输出:-