在iOS中运行长任务时加载“叠加”

Question

在执行长任务时，在Swift IOS应用程序中加载叠加层的示例是什么。从远程服务器加载数据的示例。我用谷歌搜索，但没有找到任何答案。

更新：

感谢@Sebastian Dressler这是一个简单的方法。我更新了我的代码并且运行很酷

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(view: UIView) {

        overlayView.frame = CGRectMake(0, 0, 80, 80)
        overlayView.center = view.center
        overlayView.backgroundColor = UIColor(hex: 0x444444, alpha: 0.7)
        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)
        view.addSubview(overlayView)

        activityIndicator.startAnimating()
    }

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

让我们使用：

LoadingOverlay.shared.showOverlay(self.view)
//To to long tasks
LoadingOverlay.shared.hideOverlayView()

Answer 1

上面的答案添加了加载视图，但它不会阻止屏幕上的点击事件，也不会为屏幕的其余部分提供叠加。您可以按如下方式实现：

let alert = UIAlertController(title: nil, message: "Please wait...", preferredStyle: .Alert)

alert.view.tintColor = UIColor.blackColor()
let loadingIndicator: UIActivityIndicatorView = UIActivityIndicatorView(frame: CGRectMake(10, 5, 50, 50)) as UIActivityIndicatorView
loadingIndicator.hidesWhenStopped = true
loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.Gray
loadingIndicator.startAnimating();

alert.view.addSubview(loadingIndicator)
presentViewController(alert, animated: true, completion: nil)

Swift 3.0

let alert = UIAlertController(title: nil, message: "Please wait...", preferredStyle: .alert)

let loadingIndicator = UIActivityIndicatorView(frame: CGRect(x: 10, y: 5, width: 50, height: 50))
loadingIndicator.hidesWhenStopped = true
loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
loadingIndicator.startAnimating();

alert.view.addSubview(loadingIndicator)
present(alert, animated: true, completion: nil)

Swift 4.0和更新版本

let alert = UIAlertController(title: nil, message: "Please wait...", preferredStyle: .alert)

let loadingIndicator = UIActivityIndicatorView(frame: CGRect(x: 10, y: 5, width: 50, height: 50))
loadingIndicator.hidesWhenStopped = true
loadingIndicator.style = UIActivityIndicatorView.Style.gray
loadingIndicator.startAnimating();

alert.view.addSubview(loadingIndicator)
present(alert, animated: true, completion: nil)

你可以隐藏它如下：

dismiss(animated: false, completion: nil)

它将显示如下：

Answer 2

只需创建一个叠加视图，您可以将其添加到父视图中，并在完成任务后将其删除，例如添加它：

var overlay : UIView? // This should be a class variable

[ ... ]

overlay = UIView(frame: view.frame)
overlay!.backgroundColor = UIColor.blackColor()
overlay!.alpha = 0.8

view.addSubview(overlay!)

删除：

overlay?.removeFromSuperview()

Answer 3

模糊背景+活动指标，Swift 5示例

extension UIView {
    func showBlurLoader() {
        let blurLoader = BlurLoader(frame: frame)
        self.addSubview(blurLoader)
    }

    func removeBluerLoader() {
        if let blurLoader = subviews.first(where: { $0 is BlurLoader }) {
            blurLoader.removeFromSuperview()
        }
    }
}


class BlurLoader: UIView {

    var blurEffectView: UIVisualEffectView?

    override init(frame: CGRect) {
        let blurEffect = UIBlurEffect(style: .dark)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = frame
        blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        self.blurEffectView = blurEffectView
        super.init(frame: frame)
        addSubview(blurEffectView)
        addLoader()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    private func addLoader() {
        guard let blurEffectView = blurEffectView else { return }
        let activityIndicator = UIActivityIndicatorView(style: .whiteLarge)
        activityIndicator.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
        blurEffectView.contentView.addSubview(activityIndicator)
        activityIndicator.center = blurEffectView.contentView.center
        activityIndicator.startAnimating()
    }
}

Answer 4

对于像我这样迟到的人，我对@Sonrobby代码进行了一些修改。据我了解，@ Sonrobby将活动添加到每个showOverlay呼叫的叠加层。并且一些配置可以传递给init函数，只允许放置在showOverlay方法上。

我还将叠加层的背景更改为黑色，因为我的应用程序主要是白色。

这是代码：

public class LoadingOverlay{

    var overlayView : UIView!
    var activityIndicator : UIActivityIndicatorView!

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

    init(){
        self.overlayView = UIView()
        self.activityIndicator = UIActivityIndicatorView()

        overlayView.frame = CGRectMake(0, 0, 80, 80)
        overlayView.backgroundColor = UIColor(white: 0, alpha: 0.7)
        overlayView.clipsToBounds = true
        overlayView.layer.cornerRadius = 10
        overlayView.layer.zPosition = 1

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

    public func showOverlay(view: UIView) {
        overlayView.center = view.center
        view.addSubview(overlayView)
        activityIndicator.startAnimating()
    }

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

Answer 5

要添加给出的答案，如果您有时尝试运行代码，则可能会遇到问题。就个人而言，有一个场合没有正确调用showOverlay（因为我试图进入一个场景，然后在viewDidLoad期间立即调用此函数）。

如果遇到类似于我的问题，代码有一个修复，我建议改变方法。

FIX：将两个代码块作为闭包放到dispatch_async调用中，如下所示：

dispatch_async(dispatch_get_main_queue(),
 { //code });

方法：在调用代码时，对主队列执行dispatch_after调用，将调用延迟几毫秒。

理由？你只是要求用户在viewDidLoad中做太多。

如果解决方案的这个附录有帮助，我会很高兴。

-Joel Long

附：解决方案适用于XCode v6.3.2

Answer 6

更新了@sonrobby答案，通过调整大小掩码添加了背景视图和方向处理...这可以用于简单的东西

public class LoadingOverlay{

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

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

    public func showOverlay(view: UIView) {

        bgView.frame = view.frame
        bgView.backgroundColor = UIColor.gray
        bgView.addSubview(overlayView)
        bgView.autoresizingMask = [.flexibleLeftMargin,.flexibleTopMargin,.flexibleRightMargin,.flexibleBottomMargin,.flexibleHeight, .flexibleWidth]
        overlayView.frame = CGRect(x: 0, y: 0, width: 80, height: 80)
        overlayView.center = view.center
        overlayView.autoresizingMask = [.flexibleLeftMargin,.flexibleTopMargin,.flexibleRightMargin,.flexibleBottomMargin]
        overlayView.backgroundColor = UIColor.black
        overlayView.clipsToBounds = true
        overlayView.layer.cornerRadius = 10

        activityIndicator.frame = CGRect(x: 0, y: 0, width: 40, height: 40)
        activityIndicator.activityIndicatorViewStyle = .whiteLarge
        activityIndicator.center = CGPoint(x: overlayView.bounds.width / 2, y: overlayView.bounds.height / 2)

        overlayView.addSubview(activityIndicator)
        view.addSubview(bgView)
        self.activityIndicator.startAnimating()

    }

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

如果你把它添加到keywindow，它可以覆盖你的导航和标签栏......就像这样

LoadingOverlay.shared.showOverlay(view: UIApplication.shared.keyWindow!)

Answer 7

使用ATKit。

参考：https://aurvan.github.io/atkit-ios-release/index.html

ATProgressOverlay类https://aurvan.github.io/atkit-ios-release/helpbook/Classes/ATProgressOverlay.html

码：

import ATKit

ATProgressOverlay.sharedInstance.show() // Does not show network activity indicator on status bar.

ATProgressOverlay.sharedInstance.show(isNetworkActivity: true) // Shows network activity indicator on status bar.

截图：

Answer 8

斯威夫特3。

我在下面的答案中使用了@Lucho的代码，我更改了叠加背景颜色以清除并添加了微调颜色。

public class LoadingOverlay {

    var overlayView : UIView!
    var activityIndicator : UIActivityIndicatorView!

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

    init(){
        self.overlayView = UIView()
        self.activityIndicator = UIActivityIndicatorView()

        overlayView.frame = CGRect(0, 0, 80, 80)
        overlayView.backgroundColor = .clear
        overlayView.clipsToBounds = true
        overlayView.layer.cornerRadius = 10
        overlayView.layer.zPosition = 1

        activityIndicator.frame = CGRect(0, 0, 40, 40)
        activityIndicator.center = CGPoint(overlayView.bounds.width / 2, overlayView.bounds.height / 2)
        activityIndicator.activityIndicatorViewStyle = .whiteLarge
        activityIndicator.color = .gray
        overlayView.addSubview(activityIndicator)
    }

    public func showOverlay(view: UIView) {
        overlayView.center = view.center
        view.addSubview(overlayView)
        activityIndicator.startAnimating()
    }

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

Answer 9

我已经创建了一个协议，用于将您自己的视图控制器呈现为叠加层。用法很简单：

class ViewController: UIViewController, OverlayHost {
    @IBAction func showOverlayButtonPressed() {
        showOverlay(type: YourOverlayViewController.self, 
            fromStoryboardWithName: "Main")
    }
}

结果：

源代码：https://github.com/agordeev/OverlayViewController

相关文章：https://andreygordeev.com/2017/04/18/overlay-view-controller-protocols-swift/