RSS需要太长时间才能在android中加载

Question

我使用AsyncTask从RSS提要和DO​​M解析器和ArrayAdapter获取数据。

我注意到RSS Feed在屏幕上加载和显示数据的时间太长，起初我以为因为文章数量很大，但是当我限制for循环只读3篇文章时，它仍然花费太长时间展示文章！

下面

是完整的代码我使用的解析数据和主要活动

主要业务代码：

public class NewsMainActivity extends Activity implements OnItemClickListener { 
    /** Called when the activity is first created. */ 

    ListView listview; 
    List<NewsBean> arrayList; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     //Remove title bar 
     this.requestWindowFeature(Window.FEATURE_NO_TITLE); 

     setContentView(R.layout.main); 

     initComponents(); 

     if (Utils.isNetworkAvailable(this)) { 
      new MyRssReadTask() 
        .execute("feed_URL"); 

     } else { 
      Toast.makeText(this, "Please check your internet connection", Toast.LENGTH_SHORT) 
        .show(); 
     } 

    } 

    private void initComponents() { 
     listview = (ListView) findViewById(android.R.id.list); 
     listview.setOnItemClickListener(this); 

    } 

    class MyRssReadTask extends AsyncTask<String, Void, Void> { 
     ProgressDialog waitingDialog; 

     @Override 
     protected void onPreExecute() { 
      waitingDialog = new ProgressDialog(NewsMainActivity.this); 
      waitingDialog.setMessage("Loading articles, Please wait..."); 
      waitingDialog.show(); 
      super.onPreExecute(); 
     } 

     @Override 
     protected Void doInBackground(String... urls) { 

      arrayList = new NewsParser().getData(urls[0]); 

      return null; 
     } 

     @Override 
     protected void onPostExecute(Void result) { 
      waitingDialog.dismiss(); 
      setDataToListView(); 
      super.onPostExecute(result); 
     } 
    } 

    protected void setDataToListView() { 
     if (null != arrayList && arrayList.size() != 0) { 
      NewsRowAdapter objNewsRowAdapter = new NewsRowAdapter(
        NewsMainActivity.this, R.layout.row, arrayList); 

      listview.setAdapter(objNewsRowAdapter); 
     } else { 
      showToast("There was an error to get data, please try again later."); 
     } 

    } 

    void showToast(String msg) { 
     Toast.makeText(NewsMainActivity.this, msg, Toast.LENGTH_SHORT).show(); 
    } 

    public void onItemClick(AdapterView<?> parent, View view, int position, 
      long id) { 

     final NewsBean objBean = (NewsBean) arrayList.get(position); 
     Intent intent = new Intent(NewsMainActivity.this, 
       NewsDetail.class); 

     intent.putExtra("title", objBean.getTitle()); 
     intent.putExtra("description", objBean.getDescription()); 
     //intent.putExtra("pubdate", objBean.getPubDate()); 
     //intent.putExtra("creator", objBean.getCreator()); 
     intent.putExtra("link", objBean.getLink()); 

     startActivity(intent); 
    } 

新闻分析器

public class NewsParser { 


    private List<NewsBean> arrayListPasre; 

    public List<NewsBean> getData(String _url) { 
     try { 

      arrayListPasre = new ArrayList<NewsBean>(); 
      URL url = new URL(_url); 
      URLConnection con = url.openConnection(); 

      System.out.println("Connection is : " + con); 

      System.out.println("Connection InputStream is : " 
        + con.getInputStream()); 

      BufferedReader reader = new BufferedReader(new InputStreamReader(
        con.getInputStream())); 
      System.out.println("Reader us now : " + reader); 

      String inputLine; 
      String fullStr = ""; 
      while ((inputLine = reader.readLine()) != null) 
       fullStr = fullStr.concat(inputLine + "\n"); 

      InputStream istream = url.openStream(); 

      DocumentBuilder builder = DocumentBuilderFactory.newInstance() 
        .newDocumentBuilder(); 

      System.out.println("Builder : " + builder); 

      Document doc = builder.parse(istream); 

      doc.getDocumentElement().normalize(); 

      NodeList nList = doc.getElementsByTagName("item"); 

      System.out.println("nlist " + nList); 

      for (int temp = 0; temp < 3; temp++) { 

       Node nNode = nList.item(temp); 
       if (nNode.getNodeType() == Node.ELEMENT_NODE) { 

        Element eElement = (Element) nNode; 

        NewsBean objBean = new NewsBean(); 

        objBean.setTitle(getTagValue("title", eElement)); 
        objBean.setDescription(getTagValue("description", eElement)); 
        objBean.setLink(getTagValue("link", eElement)); 
        arrayListPasre.add(objBean); 
       } 
      } 

     } catch (Exception e) { 
      e.printStackTrace(); 
     } 

     return arrayListPasre; 
    } 

    private String getTagValue(String sTag, Element eElement) { 
     NodeList nlList = eElement.getElementsByTagName(sTag).item(0) 
       .getChildNodes(); 

     Node nValue = (Node) nlList.item(0); 

     return nValue.getNodeValue(); 

    } 
} 

任何建议，我将感谢！ :)

Answer 1

你不需要一次解析整个rss。你可以部分做到这一点。例如解析文档并获取rss项目数，然后仅针对3或5或10个项目调用您的异步任务。在onPostExecute（）将结果添加到适配器并调用notifydatasetchanged（）。