viewpager + webview,如何停止webview加载

时间:2012-04-03 07:06:01

标签: android webview android-viewpager

您好,

我创建了一个使用ViewPager的应用程序,所有页面都包含WebViews。 每个Webview都包含服务器图像,视频,mp3 ......

WebView设置

      public Object instantiateItem(View collection, int position) {
            .
            .
            .

            final RelativeLayout imageLayout  = (RelativeLayout)         
            inflater.inflate(R.layout.omb_webview_layout, null);
            WebView webview = (WebView) imageLayout.findViewById(R.id.video_view);
            ProgressBar pbImage = (ProgressBar) imageLayout.findViewById(R.id.progressBar1);

            webview.requestFocus(View.FOCUS_DOWN);
            webview.getSettings().setBuiltInZoomControls(false);
            webview.getSettings().setSupportZoom(true);
            webview.getSettings().setUseWideViewPort(true);
            webview.getSettings().setJavaScriptEnabled(true);
            webview.getSettings().setLoadWithOverviewMode(true);
            webview.getSettings().setUseWideViewPort(true);
            webview.setWebViewClient(new mWebViewClient());
            webview.getSettings().setPluginsEnabled(true);
            webview.clearCache(true);
            webview.clearHistory();
            if(Pbar != null) {
                webview.setWebChromeClient(new WebChromeClient() {
                 public  void onProgressChanged(WebView view, int progress)     {
                  Log.i(TAG, "webview loading progress : "+ progress);
                    if(progress == 100) {
                        try {
                            Pbar.setVisibility(ProgressBar.GONE);
                        } catch (Exception e) {
                        Log.e(TAG, "timer progress GONE : "+ progress,e);
                        }
                         }
            });
            }

问题是当页面被刷过时,也就是这一行

 Log.i(TAG, "webview loading progress : "+ progress); 

正在执行,这意味着webview正在后台加载。 如果我滑动4个或更多页面,则所有网页视图都会加载。

     destroyItem(View collection, int position, Object o) {
    Log.d("DESTROY", "destroying view at position sheetal " + position);

            RelativeLayout view = (RelativeLayout)o;

                    WebView tmp = webviewDictionary.get(position);;

            tmp.getSettings().setJavaScriptEnabled(false);
                            tmp.stopLoading();
        if(tmp != null){
                        Log.i(TAG, "sheetal webview is destroyed " +position );
                        try {
                            tmp.onPause();

                            tmp.loadDataWithBaseURL("about:blank", "<html></html>","text/html", "UTF-8", null);
                            tmp=null;
                            //  tmp.destroy();
                        }
                        catch (Exception e) {
                            Log.i(TAG, "webview destroyed Exception 0" ,e);
                        }
                    } 

如果页面不可见,如何停止后台加载? setOffscreenPageLimit(1)(表示3页prev,cur,next),

在Viewpager中,2页(表示1位置页面)未正确加载。它显示一个空白页面,我该如何解决?

提前致谢

2 个答案:

答案 0 :(得分:2)

这解决了我的问题。

我创建了一个字典,它包含3个webview,位置为关键字。

这里我在字典中添加webviews

public Object instantiateItem(View collection, int position) {
    .
    .
    .
    webviewDictionary.put(position, webView);
    .
    .
    .
}

清洁网页浏览来自字典

public void cleanAllWebViews() {

    try {

        if(webviewDictionary != null){

            Iterator<Integer> webViewIterator = webviewDictionary.keySet().iterator();

            while(webViewIterator.hasNext()) {

                Integer key=(Integer)webViewIterator.next();

                WebView webView = (WebView) webviewDictionary.get(key);


                webView.stopLoading();
                //                  webView.pauseTimers();

                webView.setWebChromeClient(null);
                webView.setWebViewClient(null);


                webView.loadDataWithBaseURL("about:blank", "<html></html>","text/html", "UTF-8", null);
                webViewIterator.remove();

            }
        }

        webviewDictionary = null;


    }catch (Exception e) {
        Log.e(TAG, "ombook last call onPauseAllWebviews  Exception",e  );
    }
}

    and 

    @Override
public void onBackPressed() {

    cleanAllWebViews();

    System.gc();

    super.onBackPressed();
}

答案 1 :(得分:1)

你试过“OffscreenPageLimit”设置为1吗?根据这篇文章,0是无效值: ViewPager.setOffscreenPageLimit(0) doesn't work as expected

另外,您是否尝试过处理页面之间切换的事件,以便每次切换页面时,当前页面的webview都会停止加载,或者开始加载空的html文件?