在 Swift 中添加和删除视图覆盖

Question

根据这个问题：Loading Screen from any Class in Swift

问题: 调用hideOverlayView()时加载覆盖视图会显示但不会隐藏。然而奇怪的是，叠加层会在一段时间后消失（出现后 15 到 30 秒）

代码：包含在FirstController.swift

中

public class LoadingOverlay{

var overlayView = UIView()
var activityIndicator = UIActivityIndicatorView()

class var shared: LoadingOverlay {
    struct Static {
        static let instance: LoadingOverlay = LoadingOverlay()
    }
    return Static.instance
}

public func showOverlay() {
    if  let appDelegate = UIApplication.sharedApplication().delegate as? AppDelegate,
        let window = appDelegate.window {
            overlayView.frame = CGRectMake(0, 0, 80, 80)
            overlayView.center = CGPointMake(window.frame.width / 2.0, window.frame.height / 2.0)
            overlayView.backgroundColor = MyGlobalVariables.UICOLORGREEN
            overlayView.clipsToBounds = true
            overlayView.layer.cornerRadius = 10

            activityIndicator.frame = CGRectMake(0, 0, 40, 40)
            activityIndicator.activityIndicatorViewStyle = .WhiteLarge
            activityIndicator.center = CGPointMake(overlayView.bounds.width / 2, overlayView.bounds.height / 2)

            overlayView.addSubview(activityIndicator)
            window.addSubview(overlayView)

            activityIndicator.startAnimating()
    }
}

public func hideOverlayView() {
    activityIndicator.stopAnimating()
    overlayView.removeFromSuperview()
}
}

并在 DataManager.swift 中调用函数为：

LoadingOverlay.shared.showOverlay()

解法：

我在后台线程上调用。根据以下答案，调用为：

dispatch_async(dispatch_get_main_queue(), { // This makes the code run on the main thread
  LoadingOverlay.shared.hideOverlayView()          
})

Answer 1

Swift 2

您是从后台线程调用 hideOverlayView() 吗？如果你是，你应该确保它在主线程上运行：

dispatch_async(dispatch_get_main_queue(), { // This makes the code run on the main thread
  LoadingOverlay.shared.hideOverlayView()          
})

Swift 3+

DispatchQueue.main.async {
  LoadingOverlay.shared.hideOverlayView()
}

在 Swift 中添加和删除视图覆盖

Adding & Removing A View Overlay in Swift

class

viewcontroller

ios

swift