Dead loop in android webview backkey for redirect href link

问题

I got to a dead loop in Android webview application with backkey while dealing with redirect links.

For example, when my webview started, it goes to link0.

In link0, there is a href link which link to link1. Link1 redrect to link2.

So if I click link1, it will go to link1, then redirect to link2. When I click backkey, it should go back to link0, in my case. But instead, it goes to link1, which redirect back to link2 again. So I never have a chance to go back.

The backkey works correctly with other links if they are not redirect links.

I googled webs for help, but didn't find related question.

By the way, the backkey works in the internet browser as expected. But not in webview.

Below is my code, for you to try. As you can see in the code, I tried both onBackPressed and onKeyDown, but neigher works.

Thanks for your kind help. I have struglling on this for a while.

==================================================================================

public class MyActivity extends Activity 
{
    private WebView myWebView;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        myWebView = (WebView) findViewById(R.id.webview);
        myWebView.getSettings().setJavaScriptEnabled(true);
        myWebView.loadUrl("http://50.112.242.120/temp/");
        myWebView.setWebViewClient(new MyWebViewClient());
    }

    private class MyWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            myWebView.loadUrl(url);
            return true;
        }
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // Check if the key event was the Back button and if there's history
        if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
            myWebView.goBack();
            return true;
        }
        // If it wasn't the Back key or there's no web page history, bubble up to the default
        // system behavior (probably exit the activity)
        return super.onKeyDown(keyCode, event);
    }
}

// main.xml
<?xml version="1.0" encoding="utf-8"?>
<WebView  xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/webview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
/>

回答1:

webview.setWebViewClient(new WebViewClient(){
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            Log.i(tag, "url = " + url);
            // view.loadUrl(url);

            // return super.shouldOverrideUrlLoading(view, url);
            return false;
        }
    });

look!!!! the important, shouldOverrideUrlLoading must return false

in shouldOverrideUrlLoading you can't invoke view.loadUrl.

回答2:

shouldOverrideUrlLoading() is called on a per-URL basis. So, if http://site1.com/ redirects to http://site2.com/, which then redirects to http://site3.com/, you are calling WebView.loadUrl() for each of these URL's. Thus each appears in the back stack.

Instead of creating a WebViewClient you probably want a WebChromeClient. WebChromeClient defines a method onCreateWindow that is only invoked when the WebView is trying to create a new window, not for every single URL it accesses.

回答3:

I had a same problem and solved it. Here is my answer.

When I click the first link(www.new.a) it automatically redirects other link(mobile.new.a). Usually the links redirect two or three, and my solution have been worked on almost every redirect links. I hope this answer help you out with annyoing redirecting links.

I finally figured out that. You need a WebViewClient with four APIs. There are shouldOverrideUrlLoading(), onPageStarted(), onPageFinished(), and doUpdateVisitedHistory() in the WebViewClient. All the APIs you need is API 1 so don't worry about.

Here is my answer. Check out that! :)

回答4:

Annoying redirects get into the backforward history. Detect when url loading is triggered by the user, and add those to the backstack instead.

private List<String> previous = new ArrayList<String>();
private String mLastUrl;
webview.setWebViewClient(new WebViewClient() {
    @Override
    public void onPageFinished(WebView view, String url) {
        Log.i("DebugDebug", "OnPageFinished " + url);
        mLastUrl = url;
        super.onPageFinished(view, url);
    }
});

webview.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View view, MotionEvent motionEvent) {
        WebView.HitTestResult hr  = ((WebView)view).getHitTestResult();
        if (hr != null && mLastUrl != null) {
            if (previous.isEmpty() || !previous.get(previous.size() - 1).equals(mLastUrl)) {
                previous.add(mLastUrl);
            }
            Log.i("DebugDebug", "getExtra = " + hr.getExtra() + "\t\t Type = " + hr.getType());
        }
        return false;
    }
});


@Override
public void onBackPressed() {
    Log.i("DebugDebug", "onBackPressed");
    int size = previous.size();
    if (size > 0){
        webview.loadUrl(previous.get(size - 1));
        previous.remove(size - 1);
    } else {
        super.onBackPressed();
    }
}

来源：https://stackoverflow.com/questions/11992478/dead-loop-in-android-webview-backkey-for-redirect-href-link

标签

android

mobile

webview