之后用户presses的Andr​​oid的WebView停不回

问题描述

我玩的WebView内YouTube视频。我能够发挥它，但是当人离开屏幕，我无法停止播放音频。

I am playing a YouTube video inside a WebView. I am able to play it, but when the person leaves the screen, I am not able to stop the audio from playing.

我试过里面的onDestroy和的onPause各种事情，或者把他们从完全，但他们似乎并没有发挥作用。

I tried various things inside onDestroy and onPause, or taking them out entirely, but they didn't seem to make a difference.

会有人知道为什么音频继续播放和应用程序被关闭后，即使没有停止，用户打开其他应用程序？

Would anyone know why the audio keeps playing and doesn't stop even after the app is turned off and the user opens other apps?

下面是我的code全班：

Here is my code for the whole class:

import com.flurry.android.FlurryAgent;

import utils.SendEmail;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.webkit.WebSettings.PluginState;
import android.widget.Button;

public class YoutubeActivity extends Activity
{
    WebView webview = null;

    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        webview = new WebView(this);

            setContentView(webview);

            webview.getSettings().setAppCacheEnabled(false);
            webview.getSettings().setJavaScriptEnabled(true);
            webview.setInitialScale(1);
            webview.getSettings().setPluginState(PluginState.ON);

            WebSettings webSettings = webview.getSettings();

            webSettings.setLoadsImagesAutomatically(true);
            webSettings.setLoadWithOverviewMode(true);
            webSettings.setBuiltInZoomControls(true);        
            webSettings.setUseWideViewPort(true);

            webview.setWebViewClient(new WebViewClient() {
                public boolean shouldOverrideUrlLoading(WebView view, String url) {
                    view.loadUrl(url);              
                    return false;
                }
            });        


            webview.setWebChromeClient(new WebChromeClient(){});

            webSettings.setDomStorageEnabled(true);
            webSettings.setAppCacheEnabled(true);
                        webSettings.setAppCachePath(getApplicationContext().getFilesDir().getAbsolutePath() + "/cache");            

            webSettings.setDatabaseEnabled(true);
            webSettings.setDatabasePath(getApplicationContext().getFilesDir().getAbsolutePath() + "/databases");

            SharedPreferences prefs = 
                    PreferenceManager.getDefaultSharedPreferences( YoutubeActivity.this);
            String url_to_watch = prefs.getString( "url_to_watch" , null ); 


            webview.loadUrl(url_to_watch);
    }



    @Override
    public void onPause()
    {
       super.onPause();

       try
       {
           if ( webview != null )
           {
               webview.clearCache(true); 
               webview.getSettings().setAppCacheEnabled(false);
               webview.stopLoading();
               webview.destroy();           
               sendEmail ("in pause " , "");
               webview = new WebView(this);
           }

           this.finish();
       }
       catch ( Exception e )
       {

       }
    }


    @Override
    public void onDestroy()
    {
       super.onDestroy();

       try
       {
           if ( webview != null )
           {
               webview = new WebView(this); // To try to reset the webview - didn't work.
           }
       }
       catch ( Exception e )
       {

       }    
    }

    @Override
    public void onStop()
    {
       super.onStop();

       FlurryAgent.onEndSession(this);

       try
       {
           if ( webview != null )
           {
               webview.clearView();
               webview.getSettings().setAppCacheEnabled(false);
               webview.stopLoading();
               webview.destroy();

               sendEmail ("in stop " , "");
           }
       }
       catch ( Exception e )
       {

       }

       this.finish();
    }   

    @Override
    protected void onResume() 
    {
        super.onResume();

        try
        {
            webview.onResume();
        }
        catch ( Exception  e )
        {

        }
    }

    @Override
    protected void onRestart() 
    {
        super.onRestart();
    }    


    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) 
    {
        if ((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBack()) 
        {
            webview.goBack();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }   

    // Subject , body
    public void sendEmail( String subject , String body )
    {
        String[] params = new String[] { "http://www.problemio.com/problems/send_email_mobile.php", subject, body };

        SendEmail task = new SendEmail();
        task.execute(params);               
    }  


    //@Override 
    public void onPageFinished(WebView view, String url) 
    { 
        //super.onPageFinished(view, url); 
        view.clearCache(true); 
    }

    public void onBackPressed ( )
    {   
        final AlertDialog.Builder linkedin_builder = new AlertDialog.Builder(this);

             linkedin_builder.setMessage("" +
                    "Go back to the home screen?")
                .setCancelable(false)            
                .setNegativeButton("YES", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) 
                    {
                        if ( webview != null )
                        {
                            webview.destroy();
                        }

                        Intent myIntent = new Intent(YoutubeActivity.this, MainActivity.class);
                        YoutubeActivity.this.startActivity(myIntent);
                    }
                })              
                .setPositiveButton("NO", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) 
                    {
                        dialog.cancel();                  
                    }
                })
;
         AlertDialog alert = linkedin_builder.create();
         alert.show();      
    }


    @Override
    protected void onStart()
    {
        super.onStart();
        FlurryAgent.onStartSession(this, "4VYNFK3V6RCZ53CZ3J32");
    }    
}

在什么可能停止播放音频，什么可能导致它有什么想法？
谢谢！

Any thoughts on what might stop the audio from playing and what may be causing it?Thank you!

推荐答案

您应该拨打：

webView.loadUrl("about:blank");

这会破坏所有的音频/视频以及Javasript对象和停止的WebView所有正在运行的功能。

It will destroy all audio/video as well as Javasript objects and stop all running functions on webview

这篇关于之后用户presses的Andr​​oid的WebView停不回的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！