jgold6/MainActivity.cs

## MainActivity.cs
using System;
using System.IO;
using System.Threading.Tasks;
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Webkit;
using Android.Widget;
using Android.OS;
using webview_external_resource.Views;
using webview_external_resource.Models;

namespace webview_external_resource
{

    [Activity(Label = "webview_external_resource", MainLauncher = true)]
    public class MainActivity : Activity
    {

        public async void SyncAssets()
        {
            string Content;
            string FullFilePath = "";
            StreamReader Reader;
            StreamWriter Writer;


           try
           {
            FullFilePath = System.IO.Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "Chrysanthemum.jpg");

                if (!File.Exists(FullFilePath))
                {
					Application.Context.Assets.Open("Chrysanthemum.jpg").CopyTo (File.OpenWrite (FullFilePath));

                }
            }
            catch (Exception ex)
            {
                throw new Exception(string.Format("Cannot copy Chrysanthemum.jpg to {0} {1}", FullFilePath, ex.ToString()));
            }

        }

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);

            var webView = FindViewById<WebView>(Resource.Id.webView);
            webView.Settings.JavaScriptEnabled = true;

            // Use subclassed WebViewClient to intercept hybrid native calls
            webView.SetWebViewClient(new HybridWebViewClient());

            // Render the view from the type generated from RazorView.cshtml
            var model = new Model1() { Text = "Text goes here" };
            var template = new RazorView() { Model = model };
            var page = template.GenerateString();
            SyncAssets();

            var myhtml = "<html> <Title>this is my html</Title> <body> This is my HTML <img src=\"Chrysanthemum.jpg\" alt=\"Chrysanthemum.jpg\" height=\"55\" width=\"55\" /> </body> </html>";

            // NOTE: I am trying to load image from /data/data/app/files/ and it fails
            string mypath = System.IO.Path.Combine("file://" + System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal) + "/");

            // NOTE: if I use the below to load image from assets then it works.
            //string mypath = "file:///android_asset/";

            webView.LoadDataWithBaseURL(mypath, myhtml, "text/html", "UTF-8", null);
        }

        private class HybridWebViewClient : WebViewClient
        {
            public override bool ShouldOverrideUrlLoading(WebView webView, string url)
            {

                // If the URL is not our own custom scheme, just let the webView load the URL as usual
                var scheme = "hybrid:";

                if (!url.StartsWith(scheme))
                    return false;

                // This handler will treat everything between the protocol and "?"
                // as the method name.  The querystring has all of the parameters.
                var resources = url.Substring(scheme.Length).Split('?');
                var method = resources[0];
                var parameters = System.Web.HttpUtility.ParseQueryString(resources[1]);

                if (method == "UpdateLabel")
                {
                    var textbox = parameters["textbox"];

                    // Add some text to our string here so that we know something
                    // happened on the native part of the round trip.
                    var prepended = string.Format("C# says \"{0}\"", textbox);

                    // Build some javascript using the C#-modified result
                    var js = string.Format("SetLabelText('{0}');", prepended);

                    webView.LoadUrl("javascript:" + js);
                }

                return true;
            }
        }
    }
}
	using System;
	using System.IO;
	using System.Threading.Tasks;
	using Android.App;
	using Android.Content;
	using Android.Runtime;
	using Android.Views;
	using Android.Webkit;
	using Android.Widget;
	using Android.OS;
	using webview_external_resource.Views;
	using webview_external_resource.Models;

	namespace webview_external_resource
	{

	[Activity(Label = "webview_external_resource", MainLauncher = true)]
	public class MainActivity : Activity
	{

	public async void SyncAssets()
	{
	string Content;
	string FullFilePath = "";
	StreamReader Reader;
	StreamWriter Writer;


	try
	{
	FullFilePath = System.IO.Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "Chrysanthemum.jpg");

	if (!File.Exists(FullFilePath))
	{
	Application.Context.Assets.Open("Chrysanthemum.jpg").CopyTo (File.OpenWrite (FullFilePath));

	}
	}
	catch (Exception ex)
	{
	throw new Exception(string.Format("Cannot copy Chrysanthemum.jpg to {0} {1}", FullFilePath, ex.ToString()));
	}

	}

	protected override void OnCreate(Bundle bundle)
	{
	base.OnCreate(bundle);

	// Set our view from the "main" layout resource
	SetContentView(Resource.Layout.Main);

	var webView = FindViewById<WebView>(Resource.Id.webView);
	webView.Settings.JavaScriptEnabled = true;

	// Use subclassed WebViewClient to intercept hybrid native calls
	webView.SetWebViewClient(new HybridWebViewClient());

	// Render the view from the type generated from RazorView.cshtml
	var model = new Model1() { Text = "Text goes here" };
	var template = new RazorView() { Model = model };
	var page = template.GenerateString();
	SyncAssets();

	var myhtml = "<html> <Title>this is my html</Title> <body> This is my HTML <img src=\"Chrysanthemum.jpg\" alt=\"Chrysanthemum.jpg\" height=\"55\" width=\"55\" /> </body> </html>";

	// NOTE: I am trying to load image from /data/data/app/files/ and it fails
	string mypath = System.IO.Path.Combine("file://" + System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal) + "/");

	// NOTE: if I use the below to load image from assets then it works.
	//string mypath = "file:///android_asset/";

	webView.LoadDataWithBaseURL(mypath, myhtml, "text/html", "UTF-8", null);
	}

	private class HybridWebViewClient : WebViewClient
	{
	public override bool ShouldOverrideUrlLoading(WebView webView, string url)
	{

	// If the URL is not our own custom scheme, just let the webView load the URL as usual
	var scheme = "hybrid:";

	if (!url.StartsWith(scheme))
	return false;

	// This handler will treat everything between the protocol and "?"
	// as the method name. The querystring has all of the parameters.
	var resources = url.Substring(scheme.Length).Split('?');
	var method = resources[0];
	var parameters = System.Web.HttpUtility.ParseQueryString(resources[1]);

	if (method == "UpdateLabel")
	{
	var textbox = parameters["textbox"];

	// Add some text to our string here so that we know something
	// happened on the native part of the round trip.
	var prepended = string.Format("C# says \"{0}\"", textbox);

	// Build some javascript using the C#-modified result
	var js = string.Format("SetLabelText('{0}');", prepended);

	webView.LoadUrl("javascript:" + js);
	}

	return true;
	}
	}
	}
	}