Loading Local HTML with WebView Xamarin Forms

Question

I am trying to load a local HTML page in a webview with Xamarin forms. I am using the basic example in the dev docs although I can get a URL to load I can't get my own HTML pages to load. This only needs to be done through Android so there is no worries about about IOS and Windows.

The Xaml:

 <WebView
    x:Name="webviewjava"></WebView>

The code behind:

 public partial class javscriptExample : ContentPage
{
    public interface IBaseUrl { string Get(); }
    public javscriptExample()
    {
        InitializeComponent();
        var source = new HtmlWebViewSource();

        source.BaseUrl = DependencyService.Get<IBaseUrl>().Get();

        webviewjava.Source = source;
    }
}

The platform specific file (LocalFile.cs): Just to note this has been set as an Android asset.

 [assembly: Dependency(typeof(LocalFiles))]
namespace maptesting.Droid
{
    public class LocalFiles: IBaseUrl
    {
        public string Get()
        {
            return "file:///android_asset/";
        }

    }
}

and under the asset's folder there is a 'TestWebPage.html', also set as an Android asset.

Although I dont know what the problem is I have put it through debug and the base url is coming back blank. Just to be clear im not getting a file not found, the screen is simply blank. Also, and Im not sure if this makes a difference. There is no syntax highlighting on 'IBaseUrl' in the LocalFiles.cs file. So I'm not sure if it can 'see' it.

Any ideas?

Answer 1

I am also suffering with the same issue,but I resolved in the following way

Use "UrlWebViewSource" instead of "HtmlWebViewSource"

var urlSource = new UrlWebViewSource();

string baseUrl = DependencyService.Get<IWebViewBaseUrl>().GetBaseUrl();
string filePathUrl = Path.Combine(baseUrl, "imprint.html");
urlSource.Url = filePathUrl;
WebBrowser.Source = urlSource;

Answer 2

You must check the file properties for Build Action = BundleResource

Try this code to load local html file

var source = new HtmlWebViewSource();
        string url = DependencyService.Get<IBaseUrl>().GetBaseUrl();
        string TempUrl = Path.Combine(url, "terms.html");
        source.BaseUrl = url;
        string html;
        try
        {
            using (var sr = new StreamReader(TempUrl))
            {
                html = sr.ReadToEnd();
                source.Html = html;
            }
        }
        catch(Exception ex){
            Console.WriteLine(ex.Message);
        }

Implementations of the interface for each platform must then be provided

iOS

[assembly: Dependency(typeof(BaseUrl))]
namespace yournamespace
{
   public class BaseUrl: IBaseUrl
   {
      public string GetBaseUrl()
      {
        return NSBundle.MainBundle.BundlePath;
      }
   }
}

Android

[assembly: Dependency (typeof(BaseUrl))]
 namespace yournamespace {
   public class BaseUrl_Android : IBaseUrl {
      public string Get() {
        return "file:///android_asset/";
     } 
   }
 }