添加&在Swift中删除视图覆盖 [英] Adding & Removing A View Overlay in Swift

问题描述

从此问题开始：从Swift中的任何类加载屏幕

问题：加载叠加视图将显示，但在调用hideOverlayView（）时不会隐藏。奇怪的是，重叠会在一段时间后（在它出现后15到30秒）消失。

Issue: The loading overlay view will display but will not hide when hideOverlayView() is called. Oddly however, the overlay disappears after some time (15 to 30 seconds after it appears)

代码：包含在 FirstController.swift

Code: Contained in FirstController.swift

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()
}
}

在 DataManager.swift 中的函数中调用：

LoadingOverlay.shared.showOverlay()

解决方案：

我在后台线程调用。根据下面的答案，调用：

I was calling on a background thread. As per the answers below, call as:

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

推荐答案

您是从后台主题调用 hideOverlayView（）吗？如果你是，你应该确保它运行在主线程：

Are you calling hideOverlayView() from a background thread? If you are, you should make sure it runs on the main thread:

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

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