Android – 退出WebView时,音频仍然播放

我有这个代码,它的唯一的问题是,如果我离开WebView,甚至关闭该应用程序,甚至按下电源,播客的音频继续播放.

有人会知道如何阻止吗？

这是代码：

public class podcastsActivity extends BaseActivity //implements ActionBar.onNavigationListener 
{    
    WebView webview = null;

    @Override
    public void onCreate(Bundle savedInstanceStatE) 
    {
        //setTheme(R.style.Theme_Sherlock_Light);
        super.onCreate(savedInstanceStatE);
        //setContentView(R.layout.podcasts);


        webview = new WebView(this);
        webview.getSetTings().setAppCacheEnabled(false);
        webview.getSetTings().setJavaScriptEnabled(true);
        webview.seTinitialScale(1);
        webview.getSetTings().setPluginState(PluginState.oN);

        webview.setWebViewClient(new WebViewClient() {
            @Override
            public Boolean shouldOverrideUrlLoading(WebView view,String url) {
                view.loadUrl(url);
                return true;
            }
        });




        //webSetTings.setBuilTinZoomControls(true);


        WebSetTings webSetTings = webview.getSetTings();
        webSetTings.setJavaScriptEnabled(true);
        webSetTings.setBuilTinZoomControls(true);
        //webSetTings.getMediaPlayBACkrequiresUserGesture();
        webSetTings.setAllowContentAccess(true);
        webSetTings.setEnableSmoothTransition(true);
        webSetTings.setLoadsImagesAutomatically(true);
        webSetTings.setLoadWithOverviewmode(true);
        webSetTings.setSupportZoom(true);
        webSetTings.setUseWideViewPort(true);

        setContentView(webview);
        webview.loadUrl("http://www.stitcher.com/podcast/entrepreneuronfirecom/entrepreneur-on-fire-tim-ferriss-other-incredible-entrepreneurs");           

    }

//  public void onBACkPressed ( )
//  {
//      Class.forName("com.***.HTML5WebView").getmethod("onPause",(Class[]) null).
//      invoke(html5WebView,(Object[]) null);
//  }


    @Override
    public Boolean onKeyDown(int keyCode,KeyEvent event) 
    {
        if ((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBACk()) 
        {
            webview.goBACk();
            return true;
        }
        return super.onKeyDown(keyCode,event);
    }       

    @Override
    public void onStop()
    {
       super.onStop();
       // your code

       webview.clearView();
    }