使用swift在WKWebView上显示活动指示器
使用swift在WKWebView上显示活动指示器
提问于 2015-03-31 23:41:35
我正在编写以下代码，并试图在页面加载时在视图中显示活动指示器。
我尝试实现WKNavigationDelegate方法，但失败了，因为什么都没有显示出来。
对如何解决这个问题有什么建议吗？
我没有在任何地方设置SupportWebView视图委托 anywhere，但是我不知道如何在swift中这样做。
import UIKit
import WebKit
class SupportWebView: UIViewController, WKNavigationDelegate {
@IBOutlet var containerView : UIView? = nil
var webView: WKWebView?
override func loadView() {
super.loadView()
self.webView = WKWebView()
self.view = self.webView
}
override func viewDidLoad() {
super.viewDidLoad()
var dataManager = DataManager.sharedDataManager()
var url = dataManager.myValidURL
var req = NSURLRequest(URL:url!)
self.webView!.loadRequest(req)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func webView(webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
UIApplication.sharedApplication().networkActivityIndicatorVisible = true
}
func webView(webView: WKWebView, didFinishNavigation navigation: WKNavigation!) {
UIApplication.sharedApplication().networkActivityIndicatorVisible = false
}
}回答 3
Stack Overflow用户
发布于 2016-01-14 05:23:28
如注释所示，您忘记了设置webView委托：
override func loadView() {
super.loadView()
self.webView = WKWebView()
self.webView.navigationDelegate = self
self.view = self.webView
}Stack Overflow用户
发布于 2018-03-23 21:22:18
您应该将委托方法用于所有其他目的，但关键路径监视可以很好地实现这一目的。
下面是一个运行良好的Swift 4实现。
// Somewhere in your view controller
private var loadingObservation: NSKeyValueObservation?
private lazy var loadingIndicator: UIActivityIndicatorView = {
let spinner = UIActivityIndicatorView()
spinner.translatesAutoresizingMaskIntoConstraints = false
spinner.color = .black
return spinner
}()
override func viewDidLoad() {
super.viewDidLoad()
// Setup...
loadingObservation = webView.observe(\.isLoading, options: [.new, .old]) { [weak self] (_, change) in
guard let strongSelf = self else { return }
// this is fine
let new = change.newValue!
let old = change.oldValue!
if new && !old {
strongSelf.view.addSubview(strongSelf.loadingIndicator)
strongSelf.loadingIndicator.startAnimating()
NSLayoutConstraint.activate([strongSelf.loadingIndicator.centerXAnchor.constraint(equalTo: strongSelf.view.centerXAnchor),
strongSelf.loadingIndicator.centerYAnchor.constraint(equalTo: strongSelf.view.centerYAnchor)])
strongSelf.view.bringSubview(toFront: strongSelf.loadingIndicator)
}
else if !new && old {
strongSelf.loadingIndicator.stopAnimating()
strongSelf.loadingIndicator.removeFromSuperview()
}
}
}Stack Overflow用户
发布于 2019-02-26 18:35:20
请，下面的代码是工作的fineSwift 4.2。
@IBOutlet weak var wv: WKWebView!
@IBOutlet weak var activityIndicator: UIActivityIndicatorView!
override func viewDidLoad() {
super.viewDidLoad()
loadYoutube(videoID: "KqNS7uAvOxk")
}现在加载Youtube视频
func loadYoutube(videoID:String) {
guard let youtubeURL = URL(string: "https://www.youtube.com/embed/\(videoID)")
else { return }
wv.load( URLRequest(url: youtubeURL) )
wv.navigationDelegate = self
}在下面的函数中实现：
func showActivityIndicator(show: Bool) {
if show {
activityIndicator.startAnimating()
} else {
activityIndicator.stopAnimating()
}
}实现下面这三个委托方法：
func webView(_ webView: WKWebView, didFinish navigation:
WKNavigation!) {
showActivityIndicator(show: false)
}
func webView(_ webView: WKWebView, didStartProvisionalNavigation
navigation: WKNavigation!) {
showActivityIndicator(show: true)
}
func webView(_ webView: WKWebView, didFail navigation:
WKNavigation!, withError error: Error) {
showActivityIndicator(show: false)
}如果它不工作，请让我知道。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/29372720
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