WebView - Youtube videos playing in background on

问题:

I have an issue with WebView, basically I am loading in a forum that has embedded videos in places, if you play a video then rotate the device the video keeps playing in the background and you can get to it to stop it. This also occurs when you minimize the app. Is there a way to stop this?

This is my WebView code I am using.

super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        this.view = (WebView) findViewById(R.id.webView);

        view.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                if (url != null && url.contains("grcade")) {
                    view.loadUrl(url);
                    view.getSettings().setJavaScriptEnabled(true);
                    return true;
                } else {
                    view.getContext().startActivity(
                            new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
                    return true;
                }
            }
        });

        view.setDownloadListener(new DownloadListener() {
            public void onDownloadStart(String url, String userAgent,
                                        String contentDisposition, String mimetype,
                                        long contentLength) {
                Intent i = new Intent(Intent.ACTION_VIEW);
                i.setData(Uri.parse(url));
                startActivity(i);
            }


        });

        if(savedInstanceState == null){

            String url = "http://grcade.co.uk";
            view.getSettings().setJavaScriptEnabled(true);
            view.loadUrl(url);
            view.getSettings().setSupportZoom(true);
            view.getSettings().setBuiltInZoomControls(true);
            view.getSettings().setDisplayZoomControls(false);
            view.getSettings().setLoadWithOverviewMode(true);

            view.setBackgroundColor(Color.WHITE);

        }

        final SwipeRefreshLayout pulltoRefresh = (SwipeRefreshLayout) findViewById(R.id.pullToRefresh);

        pulltoRefresh.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                view.reload();
                pulltoRefresh.setRefreshing(false);

            }
        });
    }

    @Override
    public void onSaveInstanceState (Bundle outState)
    {
        super.onSaveInstanceState(outState);
        view.saveState(outState);
    }

    @Override
    public void onRestoreInstanceState(Bundle savedInstanceState)
    {
        super.onRestoreInstanceState(savedInstanceState);
        view.restoreState(savedInstanceState);
        view.getSettings().setJavaScriptEnabled(true);
    }

    //Main WebView Panel End

Any help would be appreciated as I am very confused, I am stopped it occuring with going back but the same method wont work as adding it in causes the app revert to the default webview URL rather than reloading the page the user was on.

Thanks.

回答1:

Pausing/Resuming the Video

The simple way to do this is to pause the WebView when you wish the video to stop playing (i.e. when the app goes into the background). This is simply accomplished by the following code:

WebView view = (WebView) findViewById(R.id.webView);
view.onPause();    // This will pause videos and needs to be called for EVERY WebView you create
view.pauseTimers(); // This will pause JavaScript and layout for ALL WebViews and only needs to be called once to affect all WebViews

The best place to handle this logic is to put your pausing code in the onPause() method of your Activity, and to resume the WebView when the activity comes back in view of the user in onResume:

WebView mWebView; // Initialize this somewhere

@Override
protected void onPause(){
    super.onPause();
    if(mWebView != null){
        mWebView.onPause();
        mWebView.pauseTimers();
    }
}

@Override
protected void onResume(){
    super.onResume();
    if(mWebView != null){
        mWebView.onResume();
        mWebView.resumeTimers();
    }
}

You may be interested in the onPause and onResume as well as the pauseTimers/resumeTimers methods in the WebView.

Handling Orientation Changes

If you don't want your Activity to restart when you rotate the screen (which will stop the WebView from being recreated) then just put

android:configChanges="orientation|screenSize|keyboardHidden|keyboard"

in the <activity> tag of your Activity in your AndroidManifest file. This is not a good practice to follow normally, but when you are using a complex native view like the WebView, it is okay to do (Android web browsers use this to avoid being recreated on rotate). What will happen when using this tag is that the layout will just be resized to fit the landscape orientation and you will have to manually handle any layout specific changes that were being handled using -port or -land folders in your resources. If you are only using one layout though then it is not a problem.

Please see this question/answer for more info on this, and note that it is not encouraged but it will work.

回答2:

When minimizing the app, you need to pause your webview. Use this code to pause your webview

Class.forName("android.webkit.WebView")
                        .getMethod("onPause", (Class[]) null)
                        .invoke(webview, (Object[]) null);

And about "Video plays even you rotate your phone", this is the functionality not a bug !