Android: How to reference asset images from a remotely loaded html page in webview

Question

I\'m trying to load/reference images from the app\'s assets folder from within a HTML page in a WebView. Unlike in most of the examples the HTML page itself is not located i

Answer 1

OK, thanks to mufumbo's answer I now found a working hack to mix local assets in remotely loaded HTML pages. Pages loaded using the WebView's loadUrl() method do not load images linked with file:///android_asset/... As a workaround you can fetch the HTML page using org.apache.http.client.methods.HttpGet.HttpGet() and then pass it to the WebView with loadDataWithBaseURL(). In this case the WebView will load resources linked with file:///android_asset/ as well as images and scripts via HTTP. Here's my customized webview code:

public class CustomWebView extends WebView {
    private String mURL;

    public void loadUrlWithAssets(final String url) {
        // copy url to member to allow inner classes accessing it
        mURL = url;

        new Thread(new Runnable() {
            public void run() {
                String html;
                try {
                    html = NetUtil.httpGETResponse(mURL);

                    // replace some file paths in html with file:///android_asset/...

                    loadDataWithBaseURL(mURL, html, "text/html", "UTF-8", "");
                }
                catch (IOException e) {
                    Log.e("CustomWebView.loadUrlWithAssets", "IOException", e);
                }
            }
        }).start();
    }
}

Please note that the whole http fetching is wrapped in the home-grown utility class NetUtil.

With this class it's possible to render HTML pages from a webserver and have some static resources like images or stylesheets loaded from the app's asset folder in order to improve loading speed and to save bandwidth.

Answer 2

This is how I do on the java part:

String myHTML = "< img src=\"file:///android_asset/myimage.jpg\""; myWebView.loadDataWithBaseURL("file:///android_asset/", myHTML, "text/html", "UTF-8", "");

cheers