Android WebView: Get Response Header HTML

Question

In my Xamarin App I am using a WebView to retrieve data from a service. The information is stored in the meta-tag of the head of the HTML.

In Xamarin.iOS I could manage to access this information with this code:

webView.LoadFinished += async (sender, args) => {
    var request = webView.Request;
    if (request != null) {
        var url = request.Url.AbsoluteString;
        var data = NSData.FromUrl(NSUrl.FromString(Url));
        var content = data.ToString();
        var splits = content.Split("<meta").ToList();

        var taggedSplit = splits.Find(x => x.Contains("myTag"));
                    if (!string.IsNullOrEmpty(taggedSplit)) {
                        // do stuff 
                    }
    }
}

But i can't find a working solution for Xamarin.Android. I tried this (Access the http response headers in a WebView) approach without success.

Maybe you can help me with this problem.

I don't think you can access request headers of the WebView in Android. — Vladyslav Matviienko, Oct 23 '19 at 05:57

score 1 · Accepted Answer · answered Oct 23 '19 at 07:21

you could get the value by inject a section of js code,here is a simple sample,you could check it.

in the activity :

protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.activity_other);         
        webView = FindViewById<WebView>(Resource.Id.webView1);
        webView.SetWebViewClient(new WebViewClientClass());
        WebSettings websettings = webView.Settings;
        websettings.JavaScriptEnabled = true;
        websettings.DomStorageEnabled = true;

        webView.AddJavascriptInterface(new Foo(this), "Foo");
        webView.LoadUrl("file:///android_asset/demo.html");

    }

  class WebViewClientClass : WebViewClient
    {

        public override void OnPageFinished(WebView view, string url)
        {

            //access to parse < meta name = "viewport" content = "get the value of content" >
            view.LoadUrl("javascript:window.Foo.showSource("
                         + "document.querySelector('meta[name=\"viewport\"]').getAttribute('content')"
                         + ");");
            base.OnPageFinished(view, url);
        }

    }

 class Foo : Java.Lang.Object
  {
     Context context;

     public Foo(Context context)
      {
        this.context = context;
      }
    [JavascriptInterface]
    [Export]
    public void showSource(string source)
    {
        // here you could get the value of meta content
        // in this example,i could get source = "width =device-width,initial-scale=1, maximum-scale=1"
        Log.Error("content", html);

    }
 }

the local html :

<html>
  <head>
    <meta name="viewport" content="width =device-width,initial-scale=1, maximum-scale=1">
  </head>
  <body>
     ...
  </body>
</html>

Android WebView: Get Response Header HTML

1 Answers1