在 swift 4 中使用 webkit 在 webView 中导航时创建活动指示器

Posted 2023-02-23

【中文标题】在 swift 4 中使用 webkit 在 webView 中导航时创建活动指示器

【英文标题】：create activity indicator when navigate in webView using webkit in swift 4

【发布时间】：2018-03-09 08:07:22

【问题描述】：

我想在我的 ios 应用程序中创建一个 wkwebview，并且我想向它添加一个活动指示器。我希望当我们单击 webview 中的所有按钮或部分时，它会出现活动指示器。你能给我一些代码来做到这一点吗？这是我现在的代码。它只在开始加载网站时显示指示器，但当我们点击该过程时，指示器不出现。

import UIKit
import WebKit

class ViewController: UIViewController,WKNavigationDelegate,UIWebViewDelegate 

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

    override func viewDidLoad() 
        super.viewDidLoad()

        self.view.addSubview(self.activityIndicator)

        self.view.addSubview(self.webView)

        let url:URL = URL(string : "https://www.facebook.com/")!
        let urlRequest : URLRequest = URLRequest(url: url)
        webView.load(urlRequest)

        //activity indicator
        self.webView.addSubview(self.activityIndicator)
        self.activityIndicator.startAnimating()
        self.webView.navigationDelegate = self
        self.activityIndicator.hidesWhenStopped = true

        //refresh
        webView.scrollView.bounces = true
        let refreshControl = UIRefreshControl()
        refreshControl.addTarget(self, action: #selector(ViewController.refreshWebView), for: UIControlEvents.valueChanged)
        webView.scrollView.addSubview(refreshControl)
    

    override func viewDidAppear(_ animated: Bool) 
        super.viewDidAppear( animated )

        let url:URL = URL(string : "https://www.facebook.com/")!
        let urlRequest : URLRequest = URLRequest(url: url)
        webView.load(urlRequest)
    

    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) 
        activityIndicator.stopAnimating()
    

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

    @objc func refreshWebView(sender: UIRefreshControl) 
        print("refersh")
        sender.endRefreshing()
    

【参考方案1】：

以下代码将有助于在导航栏中添加活动指示器。所以不需要创建任何子视图。这适用于 Swift 4。

import Foundation
import UIKit
import WebKit

class ContactVC: UIViewController, WKNavigationDelegate 

    var webView: WKWebView!
    var activityIndicator: UIActivityIndicatorView!

    override func loadView() 
        webView = WKWebView()
        webView.navigationDelegate = self
        view = webView

        activityIndicator = UIActivityIndicatorView(frame: CGRect(x: 0, y: 0, width: 20, height: 20))
        activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
        activityIndicator.hidesWhenStopped = true
        let barButton = UIBarButtonItem(customView: activityIndicator)
        self.navigationItem.setRightBarButton(barButton, animated: true)

    

    override func viewDidLoad() 
        super.viewDidLoad()

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

    override func didReceiveMemoryWarning() 
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    

    func showActivityIndicator(show: Bool) 
        if show 
            // Start the loading animation
            activityIndicator.startAnimating()
         else 
            // Stop the loading animation
            activityIndicator.stopAnimating()
        
    

    //MARK:- WKNavigationDelegate
    func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) 
        print("Start to load")
        showActivityIndicator(show: true)
    

    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) 
        print("Finish to load")
        title = webView.title
        showActivityIndicator(show: false)
    

    func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) 
        print(error.localizedDescription)
        showActivityIndicator(show: false)
    

    func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) 
        print(error.localizedDescription)
        showActivityIndicator(show: false)
    

【参考方案2】：

实现 didStartProvisionalNavigation 委托函数。

func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) 
    activityIndicator.startAnimating()

【讨论】：

非常感谢先生 :)