将数据从数据库填充到OnScrollListener上的ListView不起作用

public class BabyNamesActivity extends ListActivity { 

    public ArrayList<HashMap<String, String>> List1, List2, List3; 
    public ListView lv; 
    public BabyNamesActivity bnaInstance = null; 

     this.getListView().setOnScrollListener(new OnScrollListener(){ 

      //useless here, skip! 
      @Override 
      public void onScrollStateChanged(AbsListView view, int scrollState) { 
      } 

      //dumdumdum   
      @Override 
      public void onScroll(AbsListView view, int firstVisibleItem, 
        int visibleItemCount, int totalItemCount) { 


       if(firstVisibleItem + visibleItemCount == totalItemCount) 
       { 

     bnaInstance.fillListNew(10);  //NOT WORKING HERE 
       } 

    } 
    }); 


     fillList(1);     // WORKING HERE 
     fillListNew(10);    // WORKING HERE 


} 


public void fillList (int RecordNo) 
    { 

     List1=myFun(RecordNo); 

     ListAdapter adapter = new SimpleAdapter(this, List1 , R.layout.main, 
       new String[] { "name", "meaning", "gender" }, 
       new int[] { R.id.item_babyname, R.id.item_meaning, R.id.item_gender }); 

     lv = getListView();  
     lv.setAdapter(adapter);  
}; 



public ArrayList<HashMap<String, String>> myFun (int Start) 
         { 
      ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();   
      JSONObject json = JSONfunctions.getJSONfromURL("http://localhost/Andriod/babynames.php".concat("?start=").concat(Integer.toString(Start))); 

      try{ 

       JSONArray babynames = json.getJSONArray("babynames"); 

       for(int i=0;i<babynames.length();i++){      
        HashMap<String, String> map = new HashMap<String, String>();  
        JSONObject e = babynames.getJSONObject(i); 

        map.put("id", String.valueOf(i)); 
        map.put("name", "" + e.getString("babyName")); 
        map.put("meaning", e.getString("meaning")); 
        map.put("gender", e.getString("gender")); 

        mylist.add(map);    
       }  
      }catch(JSONException e)  { 

       Toast.makeText(BabyNamesActivity.this, e.toString() , Toast.LENGTH_LONG).show(); 
       Log.e("log_tag", "Error parsing data "+e.toString()); 

      } 

      return mylist; 
};

来源

2012-01-16 Rajesh

你是否在logcat中出现错误？ – kosa 2012-01-16 01:07:44

应用程序在强制关闭时出现错误日志 - 01-16 00：44：28.726：E/AndroidRuntime（232）：未捕获的处理程序：由于未捕获的异常导致主线程退出 01-16 00：44：28.736：E/AndroidRuntime （232）：java.lang.RuntimeException：无法启动活动ComponentInfo {com.gotit.babynames/com.got.babynames.BabyNamesActivity}：java.lang.NullPointerException – Rajesh 2012-01-16 01:29:07

我认为你不需要binstance.filllist ....，只是fillList ...应该够了。试一下。 – kosa 2012-01-16 02:03:31

它在实现AsyncTask后工作。

来源

2012-05-31 11:19:53 Rajesh

将数据从数据库填充到OnScrollListener上的ListView不起作用

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