Swift WKWebView加载H5页面，主动停止视频播放

开发过程中有页面通过WKWebView加载的h5页面，h5页面带视频播放功能，想离开页面时，跟H5无交互的停止视频播放，方式如下：

   public override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        if let webCell = self.webCell {
            webCell.webV.evaluateJavaScript("var videos = document.getElementsByTagName('video');for (var i=0;i < videos.length;i++){videos[i].pause();}") { obj, error in
                hvm_print("executeJsFunctionError -->\(error)", classObj: self, line: #line)
            }
        }
    }