var wk:WKWebView!

    var progBar:UIProgressView!    //定义的进度条

    override func viewDidLoad() {

        super.viewDidLoad()

        self.wk = WKWebView(frame: self.view.frame)

        let theConfiguration = WKWebViewConfiguration()

        theConfiguration.userContentController = WKUserContentController() // 通过js与webview内容交互配置

        let  frame = CGRect(x: ,y : , width: self.view.frame.width, height:self.view.frame.height) //定位wk位置

        wk = WKWebView(frame: frame, configuration: theConfiguration)

        wk.allowsLinkPreview = true

        self.wk.load(NSURLRequest(url:NSURL(string:"http://www.baidu.com/")! as URL) as URLRequest) //要在info.plist中添加对http的支持

        self.view.addSubview(self.wk)

        // add your self view here

        // add back <- icon to back to previous page

    }

    //视图已经加载完后执行

    override func viewDidAppear(_ animated: Bool){

        super.viewDidAppear(animated)

        self.wk.uiDelegate = self //实现协议，进度条和获取网页标题需要用到

        self.wk.navigationDelegate = self //网页间前进后退要用到

        //生成进度条

        progBar = UIProgressView(frame: CGRect(x: , y: , width: self.view.frame.width, height: ))

        progBar.progress = 0.0

        progBar.tintColor = UIColor.blue

        self.view.addSubview(progBar)

        //注册进度条监听事件

        self.wk.addObserver(self, forKeyPath: "estimatedProgress", options: NSKeyValueObservingOptions.new, context: nil)

        //注册网页标题监听事件

        self.wk.addObserver(self, forKeyPath: "title", options: NSKeyValueObservingOptions.new, context: nil)

    }

class LxxmForSwift: UIViewController, WKNavigationDelegate, WKUIDelegate， UINavigationControllerDelegate {

}

    //这里添加了estimatedProgrees和title两个监听事件

   override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

        if keyPath == "estimatedProgress" {

            self.progBar.alpha = 1.0

            progBar.setProgress(Float(wk.estimatedProgress), animated: true)

            if(self.wk.estimatedProgress >= 1.0){

                UIView.animate(withDuration: 0.3, delay: 0.1, options: UIViewAnimationOptions.curveEaseInOut, animations: { () -> Void in

                    self.progBar.alpha = 0.0

                }, completion: { (finished:Bool) -> Void in

                    self.progBar.progress =

                })

            }

        } else if keyPath == "title" {

            self.titleForWeb.title = self.wk.title //这里titleForWeb是我自己定义的一个导航bar

            print(wk.title!)

        }

    }

    override func viewWillDisappear(_ animated: Bool) {

        wk.removeObserver(self, forKeyPath: "estimatedProgress")

        wk.removeObserver(self, forKeyPath: "title")

    }

　　//把这两个方法加到代码里，配合之前的 self.wk.uiDelegate = self 即可。

　　//监听js调用提示框

    func webView(_ webView: WKWebView, runJavaScriptAlertPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping () -> Void) {

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

        alert.addAction(UIAlertAction(title: "确定", style: .default, handler: { (action) in

            completionHandler()

        }))

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

    }

    // 监听通过JS调用q确认框

    func webView(_ webView: WKWebView, runJavaScriptConfirmPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping (Bool) -> Void) {

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

        alert.addAction(UIAlertAction(title: "确定", style: .default, handler: { (action) in

            completionHandler(true)

        }))

        alert.addAction(UIAlertAction(title: "取消", style: .default, handler: { (action) in

            completionHandler(false)

        }))

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

    }