title: Dynamic webview height issue in swift
body: <p>i have a VC in which on top i have a view under it i have placed a webview in which i'm loading data from URL, under the webview there is another view. Now i'm trying to make dynamic height of webview according to content inside it. It's height works fine but when i scroll the VC it scroll till webview content and does not show view under it. My view looks like this,
  <a href="http://vid.us/qas8i8" rel="nofollow noreferrer">enter image description here</a></p>
  
  <p>I'm making webview dynamic height like this,</p>
  
  <pre><code>func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
  
      webView.frame.size.height = 1
      webView.frame.size = webView.sizeThatFits(.zero)
      webView.scrollView.isScrollEnabled=false;
  
     webView.evaluateJavaScript("document.documentElement.scrollHeight", completionHandler: { (height, error) in
          self.webViewHeight.constant = height as! CGFloat
          //self.bgViewHeight.constant = webView.scrollView.contentSize.height + 500
      })
  }
  </code></pre>
  
  <p>It works fine but when i scroll VC it does not show view under it.
  This is how VC looks when i run the app,
  <a href="http://vid.us/qas8i8" rel="nofollow noreferrer">enter link description here</a></p>