self.mapWebView.delegate = self
let mapHtmlFile = Bundle.main.path(forResource: "map", ofType: "html")
let html = try? String(contentsOfFile: mapHtmlFile!, encoding: String.Encoding.utf8)
self.mapWebView.loadHTMLString(html!, baseURL: nil)

func webViewDidFinishLoad(_ webView: UIWebView) {
        webView.frame.size.height = 1
        webView.frame.size = webView.sizeThatFits(.zero)
        webView.scrollView.isScrollEnabled=false;
        self.cnDirectionWebViewHeight.constant = webView.scrollView.contentSize.height
        webView.scalesPageToFit = true

       // tried following code. Doesn't work
       //webView.frame.size.height = 1
       //webView.frame.size = webView.sizeThatFits(CGSize.zero)
   }