How to load files from Android Assets folder in Webview

I am using Xamarin Forms 2.2.0.3, I am trying to access some .html and .js files from Android Assets folder and show them in Webview, but its not working for me.

I tried these two ways to achieve this:

1. "file:///android_asset/MyFiles/main.html"

   But not getting the correct Url it seems

2. AssetManager assets = Android.App.Application.Context.Assets;
   var asset = Android.App.Application.Context.Assets.Open ("MyFiles");

   this is also not working, and getting invalid path error.

If I am adding any files directly in Assets folder then I am able to read it but If I am adding it in some folder then its not working.

Can any one suggest me how to access files from folders in Assets folder in Xamarin Android?