Ios Don'；当UIActivityIndicatorView加载速度足够快（少于一秒）时，它不会显示UIActivityIndicatorView

我想知道当数据加载速度足够快（例如不到一秒钟）时，是否可以不显示

UIActivityIndicatorView

在我当前的应用程序中，每次新的搜索都会重新加载我的收藏视图，但有时搜索速度非常快，指示器视图会闪烁并立即消失，给应用程序带来一种丑陋的整体感觉

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因此，基本上我的问题是：当加载足够快时，我可以“禁用”UIActivityIndicator视图吗？

一旦你向服务器发送响应，设置一个计时器。如果你在几秒钟内收到响应，你可以隐藏uiactivity indicator

activityindicator.hidden =false 

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对UIActivityIndicatorView进行子类化，并重写setter以显示视图。在此处设置计时器，使其仅在2秒后显示。如果在此之前取消活动指示器，则不会显示任何内容。

如果无法知道您的数据使用了多少时间，您可以使用计时器或延迟功能延迟显示您的

UIActivityIndicator

：

func delay(seconds seconds: Double, completion:()->()) {
        let popTime = dispatch_time(DISPATCH_TIME_NOW, Int64( Double(NSEC_PER_SEC) * seconds ))

        dispatch_after(popTime, dispatch_get_main_queue()) {
            completion()
        }
}

使用：

self.delay(seconds: 0.5, completion: {
            // show my activityindicator 
}

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如果您使用Alamofire框架来处理网络流，您还可以使用良好的AlamofireNetworkActivityIndicator来处理：

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您可以简单地延迟启动指示器动画：

var inUpdate = false
let indicatorView = UIActivityIndicatorView()

func startUpdate()
{
    // go to update request
    // do not forget to set inUpdate property to false in update completeon

    inUpdate = true
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(Double(NSEC_PER_SEC))), dispatch_get_main_queue())
        {
            [weak self] in
            if self?.inUpdate == true
            {
                self!.indicatorView.startAnimating()
            }
        }
}

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使用这个类，如果回调发生的时间少于1秒，我不会显示活动指示器

final class DelayableActivityIndicatorView: UIActivityIndicatorView {
    static let kDefaultDelay: TimeInterval = 1
    private var inProgress = false

    func startAnimatingWithDelay(_ delay: TimeInterval = kDefaultDelay) {
        inProgress = true
        DispatchQueue.main.asyncAfter(deadline: .now() + delay) {
            if self.inProgress == true {
                self.startAnimating()
            }
            self.inProgress = false
        }
    }

    func stopAnimatingWithDelay() {
        inProgress = false
        stopAnimating()
    }
}

要在视图控制器中使用它

class MyViewController : UIViewController {
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        self.view = view
    }

    var spinner: DelayableActivityIndicatorView = {
       let view = DelayableActivityIndicatorView(style: .gray)
        view.translatesAutoresizingMaskIntoConstraints = false
        return view
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        view.addSubview(spinner)
        spinner.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        spinner.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true

        spinner.startAnimatingWithDelay()

        // replace this code with your network api
        DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
            self.spinner.stopAnimatingWithDelay()
        }
    }
}

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view.hidden=true

？但问题是，如果加载时间为1.5秒，则在第一秒钟它不会显示任何内容，然后闪烁0.5秒

class MyViewController : UIViewController {
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        self.view = view
    }

    var spinner: DelayableActivityIndicatorView = {
       let view = DelayableActivityIndicatorView(style: .gray)
        view.translatesAutoresizingMaskIntoConstraints = false
        return view
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        view.addSubview(spinner)
        spinner.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        spinner.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true

        spinner.startAnimatingWithDelay()

        // replace this code with your network api
        DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
            self.spinner.stopAnimatingWithDelay()
        }
    }
}