WebView loadUrl works only once

问题:

EDIT: I worked on this project years ago and unfortunately I cannot verify if any of the answers is working in the given scenario.

I am having hard time with one WebView which should show our blog. When initilized, it works just fine. The user can navigate to different links within the WebView. To get back to the blog, there is a button outside the WebView which should load the main blog site again.

The problem is, that nothing is loaded after the second call to loadUrl. Here is my code:

private WebView wv;

        @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

            this.setContentView(R.layout.blog);

    wv = (WebView) findViewById(R.id.blog_webview);
    wv.getSettings().setJavaScriptEnabled(true);
    wv.setWebViewClient(new WebViewClient() {

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon {
            MyLog.logDump("onPageStarted: " + url);
        }

        @Override
        public void onPageFinished(WebView view, String url) {
                            MyLog.logDump("onPageFinished: " + url);
        }
    });

    wv.loadUrl(Constants.BLOG_URL);
}

The function called by my OnClickListener is the following:

    public void reLoadUrl() {
        wv.loadUrl(Constants.BLOG_URL);

}

But despite that the logs in onPageFinished and onPageStarted show that my wv.loadUrl is being invoked and that it's loading the correct url, the content in the webview itself doesn't change. I've tried clearing the cache, the history, the view, tried different WebSettings, tried to use webView.goBack() - not result. Also those ideas don't work: Strange webview goBack issue in android

Sometimes, the reLoadUrl shows the desired result - but once it fails it no longer can be made to work again. Any ideas what could be happening? I did try to read the WebView code but I couldn't find anything that could help me.

The only thing that I can add, is that we are using some ad networks which are heavily dependent on webViews - I tried to turn those down, but I didn't remove the libraries so I am not sure that they are not the culprit.

Any ideas??

回答1:

Use exact in below sequence.

   wv.clearCache(true);
   wv.clearView();
   wv.reload();
   wv.loadUrl("about:blank");
   wv.loadData(Constants.BLOG_URL);

回答2:

I have spent the last day or so working on an application that utilised a WebView. I did have a few issues with loading data into the WebView.

I am not entirely sure this would work but perhaps replace this code:

public void reLoadUrl() {
    wv.loadUrl(Constants.BLOG_URL);

}

with this code:

public void reLoadUrl() {

    wv.clearView();
    wv.loadUrl(Constants.BLOG_URL);

}

maybe when you clear the WebView it will solve the issue

回答3:

I'd suggest you try recreating the WebView every time you use it and see if that makes any difference.

First save context, layout parms and parent.

Context context = wb.getContext();
ViewGroup.LayoutParams lp = wv.getLayoutParams();
ViewGroup parent = (ViewGroup)wv.getParent();

Then stop it loading and remove the view from its parent.

wv.stopLoading();
parent.removeView(wv);

Then recreate and add it back.

wv = new WebView(context);
parent.addView(wv, lp);

That may be other properties that you'll need to restore, but that's the general idea.

回答4:

Try to load a blank page before:

wv.loadUrl("about:blank");
wv.clearHistory();
wv.clearView();
wv.loadUrl(Constants.BLOG_URL);

Edit: This is a code I used before because I had problems with this too, please try it.

回答5:

Try setting a WebChrome client. The webview needs support of WebChrome Clint to work properly in some cases.

wv.setWebChromeClient(new WebChromeClient());

回答6:

Just make a method in which you'll flush an reinitialize whole WebView and call it from reLoadUrl().

void loadWebView() {
    wv = (WebView) findViewById(R.id.blog_webview);
    wv.getSettings().setJavaScriptEnabled(true);
    wv.setWebViewClient(new WebViewClient() {

    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon {
        MyLog.logDump("onPageStarted: " + url);
    }

    @Override
    public void onPageFinished(WebView view, String url) {
                        MyLog.logDump("onPageFinished: " + url);
    }
});

wv.loadUrl(Constants.BLOG_URL);
}

public void reLoadUrl() {
   loadWebView();
}

回答7:

@override
public void onFormResubmission(WebView view, Message dontResend, Message resend){
   resend.sendToTarget();
}

回答8:

I had the same issue, calling resumeTimers() solved the problem for me...

回答9:

I am facing the same issue and got it working by following steps:

webView.clearCache(true);
webView.loadUrl("Url");

and I got the multiple url loaded successfully.

回答10:

I was facing the same problem and finally able to manage to solve this.I am new to android not sure this good or bad but it works for me.I simply clear catch from web view and destroy and re-create before reloading another url .

mWebView.clearCache(true);
// destroy before reload new url
parentView.removeView(mWebView);
mWebView.clearHistory();    
mWebView.destroy();

Though mWebView.destroy(); generate an error "java.lang.Throwable: Error: WebView.destroy() called while still attached!" and i search it but does not get any solution and many say it does not affect application till now(I still does not know solve this N.B: I use WebChromeClient ) .

回答11:

In onCreate, instead of using wv.loadUrl(Constants.BLOG_URL); , just use wv.loadDataWithBaseURL(baseUrl, readFileAsString("index.html") , mimeType, "UTF-8", null);

回答12:

I was facing the same issue. I was creating a new Webview everytime. Just first destroy your previous webView before creating a new one. I hope this help!! Make your webview a global variable. Like -

Webview w;

then before creating a new webview just destroy the previous one

                if(null != w)
                {
                    //destroy the previous webview, before creating the new one
                    w.destroy();
                }
                w= new WebView(activity);

回答13:

Call this method in onPause()

 private void pauseWebView() {
            try {
                Class.forName("android.webkit.WebView")
                        .getMethod("onPause", (Class[]) null)
                        .invoke(webview, (Object[]) null);

            } catch(ClassNotFoundException cnfe) {

            } catch(NoSuchMethodException nsme) {

            } catch(InvocationTargetException ite) {

            } catch (IllegalAccessException iae) {

            }
        }

回答14:

I faced the same issue and none of the above solution worked for me. So I fixed it by reloading WebView using JavaScript as follows:

webView.loadUrl( "javascript:window.location.reload( true )" );

Also JavaScript needs to be enabled for the WebView:

webView.getSettings().setJavaScriptEnabled(true);