如何将活动指标添加到WKWebView(Swift 3)

Question

我的应用程序中有一个wkwebview,我想为它添加一个活动指示器.我希望它能够在webview加载时出现,并在加载完成后消失,它会消失.你能给我一些代码吗？这是我现在的代码:

@IBOutlet weak var Activity: UIActivityIndicatorView!
var webView : WKWebView!


@IBOutlet var containerView: UIView? = nil


override func viewDidLoad() {
    super.viewDidLoad()

    guard let url = URL(string: "http://ifunnyvlogger.wixsite.com/ifunnyvlogger/app-twitter") else { return }

    webView = WKWebView(frame: self.view.frame)
    webView.translatesAutoresizingMaskIntoConstraints = false
    webView.isUserInteractionEnabled = true
    webView.navigationDelegate = self

    self.view.addSubview(self.webView)

    let request = URLRequest(url: url)
    webView.load(request)

}


func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {

    // Check if a link was clicked
    if navigationAction.navigationType == .linkActivated {

        // Verify the url
        guard let url = navigationAction.request.url else { return }
        let shared = UIApplication.shared

        // Check if opening in Safari is allowd
        if shared.canOpenURL(url) {

            // Ask the user if they would like to open link in Safari
            let alert = UIAlertController(title: "Do you want to open Safari?", message: nil, preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "Yes", style: .default, handler: { (alert: UIAlertAction) -> Void in
                // User wants to open in Safari
                shared.open(url, options: [:], completionHandler: nil)
            }))
            alert.addAction(UIAlertAction(title: "Opps, no.", style: .cancel, handler: nil))

            present(alert, animated: true, completion: nil)

        }
        decisionHandler(.cancel)
    }
    decisionHandler(.allow)
}

func webViewDidStartLoad(_ : WKWebView) {
    Activity.startAnimating()
}

func webViewDidFinishLoad(_ : WKWebView) {
    Activity.startAnimating()
}

我正在使用xcode 8和swift 3创建一个IOS应用程序

Answer 1

请在下面的代码工作正常.

@IBOutlet weak var Activity: UIActivityIndicatorView!
var webView : WKWebView!
@IBOutlet var containerView: UIView? = nil

override func viewDidLoad() {
    super.viewDidLoad()

    guard let url = URL(string: "http://www.facebook.com") else { return }
    webView = WKWebView(frame: self.view.frame)
    webView.translatesAutoresizingMaskIntoConstraints = false
    webView.isUserInteractionEnabled = true
    webView.navigationDelegate = self
    self.view.addSubview(self.webView)
    let request = URLRequest(url: url)
    webView.load(request)

    // add activity
    self.webView.addSubview(self.Activity)
    self.Activity.startAnimating()
    self.webView.navigationDelegate = self
    self.Activity.hidesWhenStopped = true

}

在这两个委托方法下面实现:

func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
    Activity.stopAnimating()
}

func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
    Activity.stopAnimating()
}

如果它不起作用,请告诉我.

Answer 2

import UIKit
import WebKit

class ViewController: UIViewController, WKNavigationDelegate, WKUIDelegate {

    var webView: WKWebView!
    var activityIndicator: UIActivityIndicatorView!

    override func viewDidLoad() {
        webView = WKWebView(frame: CGRect.zero)
        webView.navigationDelegate = self
        webView.uiDelegate = self

        view.addSubview(webView)

        activityIndicator = UIActivityIndicatorView()
        activityIndicator.center = self.view.center
        activityIndicator.hidesWhenStopped = true
        activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray

        view.addSubview(activityIndicator)

        webView.load(URLRequest(url: URL(string: "http://google.com")!))
    }

    func showActivityIndicator(show: Bool) {
        if show {
            activityIndicator.startAnimating()
        } else {
            activityIndicator.stopAnimating()
        }
    }

    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)
    }
}

Answer 3

斯威夫特 5 版本

这个概念很简单，可以移植到早期的 swift 版本。

在任何需要 Web 视图的地方，我们都会将这个类用作父类。

import UIKit
import WebKit

class CustomWebViewController: UIViewController, WKNavigationDelegate {
    var activityIndicator: UIActivityIndicatorView!

    override func viewDidLoad() {
        super.viewDidLoad()

        activityIndicator = UIActivityIndicatorView()
        activityIndicator.center = self.view.center
        activityIndicator.hidesWhenStopped = true
        activityIndicator.style = .gray
        activityIndicator.isHidden = true

        view.addSubview(activityIndicator)
    }

    func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
        activityIndicator.isHidden = false
        activityIndicator.startAnimating()
    }

    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        activityIndicator.stopAnimating()
        activityIndicator.isHidden = true
    }
}

如果我们有一个带有 webview 的 UIViewController，我们可以继承 CustomWebViewController，它会为我们处理剩下的事情。记得连接webview IBOutlet。

import UIKit
import WebKit

class FirstViewController: CustomWebViewController {

    @IBOutlet var webView: WKWebView!

    override func viewDidLoad() {
        super.viewDidLoad()
        webView.navigationDelegate = self

        let url = URL(string: "https://google.com")
        webView.load(URLRequest(url: url!))
    }
}