加载一个"；“覆盖”；在iOS中运行长任务时

在执行长任务时，在Swift IOS应用程序中加载覆盖的示例是什么。从远程服务器加载数据的示例。 我在谷歌上搜索了一下，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，它运行得很酷

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()

---

只需自己创建一个覆盖视图，将其添加到父视图中，并在任务完成后将其删除，例如添加：

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()

---

为了补充给出的答案，如果有时试图运行代码，可能会遇到问题。就个人而言，有一次showOverlay没有被正确调用（因为我试图进入一个场景，然后在viewDidLoad期间立即调用这个函数）

如果您遇到与我类似的问题，我建议您对代码进行一次修复，并改变方法

修复：将两个代码块作为闭包放置到dispatch_异步调用中，如下所示：

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

方法：调用代码时，在调用后对主队列执行分派，将调用延迟几毫秒

原因是什么？您只是要求UI在viewDidLoad期间执行太多操作

如果这个解决方案的附录有帮助，我会很高兴

-乔尔朗

---

p.S.解决方案适用于XCode v6.3.2

对于像我这样迟到的人，我对@Sonrobby代码做了一些修改。据我所知，@Sonrobby会在每次

showOverlay

调用时将活动添加到覆盖中。一些配置可以传递给init函数，只允许放置在

showOverlay

方法上

我还将覆盖层的背景改为黑色，因为我的应用程序大部分是白色的

代码如下：

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()
    }
}

---

上面的答案添加了一个加载视图，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覆盖。您可以通过以下方式实现：

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)

dismiss(animated: false, 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及更新版本

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)

您可以按如下方式隐藏它：

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)

dismiss(animated: false, completion: nil)

将显示如下： 雨燕3

我在下面的回答中使用了@Lucho的代码，我将叠加背景颜色更改为清晰，并添加了微调器颜色

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()
    }
}

---

我创建了一个协议，用于将您自己的视图控制器显示为覆盖。用法非常简单：

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

结果:

源代码：

---

相关文章：

更新了@sonrobby answer，通过调整掩码大小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()
    }
}

如果您将其添加到keywindow，它还可以浏览导航栏和选项卡栏。。。像这样的

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

---

模糊背景+活动指示器，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()
    }
}

使用ATKit

参考：

ATProgressOverlay类

代码：

截图：

---

Swift 5

class func showUniversalLoadingView(_ show: Bool, loadingText : String = "") {
    let existingView = UIApplication.shared.windows[0].viewWithTag(1200)
    if show {
        if existingView != nil {
            return
        }
        let loadingView = self.makeLoadingView(withFrame: UIScreen.main.bounds, loadingText: loadingText)
        loadingView?.tag = 1200
        UIApplication.shared.windows[0].addSubview(loadingView!)
    } else {
        existingView?.removeFromSuperview()
    }

}



 class func makeLoadingView(withFrame frame: CGRect, loadingText text: String?) -> UIView? {
    let loadingView = UIView(frame: frame)
    loadingView.backgroundColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.5)
    let activityIndicator = UIActivityIndicatorView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
    //activityIndicator.backgroundColor = UIColor(red:0.16, green:0.17, blue:0.21, alpha:1)
    activityIndicator.layer.cornerRadius = 6
    activityIndicator.center = loadingView.center
    activityIndicator.hidesWhenStopped = true
    activityIndicator.style = .white
    activityIndicator.startAnimating()
    activityIndicator.tag = 100 // 100 for example

    loadingView.addSubview(activityIndicator)
    if !text!.isEmpty {
        let lbl = UILabel(frame: CGRect(x: 0, y: 0, width: 200, height: 30))
        let cpoint = CGPoint(x: activityIndicator.frame.origin.x + activityIndicator.frame.size.width / 2, y: activityIndicator.frame.origin.y + 80)
        lbl.center = cpoint
        lbl.textColor = UIColor.white
        lbl.textAlignment = .center
        lbl.text = text
        lbl.tag = 1234
        loadingView.addSubview(lbl)
    }
    return loadingView
}

使用

showUniversalLoadingView（真实）

卸下加载器

showUniversalLoadingView(false)

---

@Ajinkya Patil回答作为参考Swift 4.0及更新版本

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)

这是一个扩展解决方案，可在所有viewController上使用，不会发生冲突

创建加载对话框+ViewContoller.swift

import UIKit

struct ProgressDialog {
    static var alert = UIAlertController()
    static var progressView = UIProgressView()
    static var progressPoint : Float = 0{
        didSet{
            if(progressPoint == 1){
                ProgressDialog.alert.dismiss(animated: true, completion: nil)
            }
        }
    }
}
extension UIViewController{
   func LoadingStart(){
        ProgressDialog.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();

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

  func LoadingStop(){
    ProgressDialog.alert.dismiss(animated: true, completion: nil)
  }
}

调用ViewController中的函数，可以在任意位置调用。像这样：

self.LoadingStart()

下面是如何停止加载对话框

self.LoadingStop()

---

Xamarin.iOS版本：

var-alert=UIAlertController.Create（string.Empty，“请稍候…”，UIAlertControllerStyle.alert）；
var alertIndicatorView=新UIActivityIndicatorView（）；
alertIndicatorView.Frame=新的CGRect（x:10，y:5，宽度：50，高度：50）；
alertIndicatorView.ActivityIndicatorViewStyle=UIActivityIndicatorViewStyle.Gray；
alertIndicatorView.HidesWhenStopped=true；
alertIndicatorView.StartAnimating（）；
添加（alertIndicatorView）；
控制器。PresentViewController（警报、真、空）；

谢谢@Sebastian Dressler，我刚刚更新了我的问题。你能把上面的代码翻译成Swift吗？不，我不这么认为。我在这里提供的内容可以用作基本框架。只需将其余部分添加到顶部即可。截至今天（2015年11月），似乎需要覆盖！。removeFromSuperView（）[注意感叹号而不是问号]可以确认

在

overlay…

removeFromSuperview（）中的小“v”几乎无法满足您的请求。而你也得不到一个简单的“翻译”。如果你在谷歌上搜索，例如使用Objective-C覆盖，你会发现一些条目如何在iOS/OS X上实现。dismissViewControllerAnimated（false，completion:nil）在XCode 8.2中不存在。它已更改为Disclose（动画：false，completion:nil）一种更安全的解除方式是：

internal func dismissAlert（）{如果让vc=self.presentedViewController，vc是UIAlertController{Disclose（动画：false，completion:nil）}

对于Swift 4.0选项，我收到此警告：

警告：尝试显示不在窗口层次结构中的视图工作正常，但在关闭后
**navigationController？.pushViewController（adminHomeVC，动画：true）**
不工作。。（swift 4）在swift 4中将
loadingIndicator.style
更改为
loadingIndicator.activityIndicatorViewStyle
，如何使用它？啊，谢谢，我真的得到了它，在uiviewcontroller中添加了self.view.addSubview（overlay）伟大的解决方案！这个答案非常有用-如果其他使用Xamarin.iOS的人需要这样做，我已经用C#重写了它。你可以在viewController中使用它来显示self.view.showBlurLoader（）和删除self.view.removeBluerLoader（），使用
bgView.frame=view.bounds
？因为
view.frame.origin
可能不同于（0,0）。覆盖的目的是覆盖提供给它的视图…它不必关心原点在哪里。。。。如果您需要覆盖整个屏幕，请将其应用于keywindow。如果您遇到过is，请告诉我