Read WebView localStorage after registration - xamarin

Question

On my Xamarin App i have a webview that hosts a "web based" registration page and login page built on React (SPA Web application). We do not want to develop that pages from scratch using Xamarin. After registration or login, React stores the access token in the web localStorage Web object.
I would like to read that token from Xamarin C# function and use it for other operations.
i succeed to read the value using javascript injection, something like:
var access_token = await webView.InjectJavascriptAsync("localStorage.getItem('access_token')");
the problem is that the value is populated only after the registration that hosted in the webview and the "Navigated" event not fires on SPA applications URL changes.
Do you know how can i read that localstorage value after registration completed in the webview container?
Something like ScriptNotify of Windows Phone would be great for me to notify Xamarin that the registration completed but couldn't find equivalent for Android and IOS.

Answer 1

as you could edit the web page,you could create a function in js and return the access token after registration completed ,you could refer to this :
Js calls methods in C#
WebSettings settings = webview.Settings;
settings.JavaScriptEnabled = true;
// load the javascript interface method to call the foreground method
webView.AddJavascriptInterface(new MyJSInterface(this), "CSharp");
webview.SetWebViewClient(new WebViewClient());
Create a C# class ：
class MyJSInterface : Java.Lang.Object
{
Context context;
public MyJSInterface (Context context)
{
this.context = context;
}
[JavascriptInterface]
[Export]
public void GetAccessToken(string accesstoken)
{
Toast.MakeText(context, accesstoken, ToastLength.Short).Show();
}
}
And then it's called in JS (in your case ,after registration completed,you could call like CSharp.GetAccessToken('accesstoken'))：
<button type="button" onClick="CSharp.GetAccessToken('Call C#')">Call C#</button>
You can refer to this document：https://github.com/xamarin/recipes/tree/master/Recipes/android/controls/webview/call_csharp_from_javascript