列表視圖的Onscroll監聽器不起作用

Question

我有一個列表視圖，當列表項目到達20個列表項目時，應該加載更多列表項目。我已添加onscroll偵聽器來執行此操作 但它沒有按照我的預期工作。

要完全理解請看這video。

我的代碼：

public class InterActivity extends Activity implements OnItemClickListener, OnItemLongClickListener 
    { 


    ListView listview; 
    List<ParseObject> ob; 
    ProgressDialog mProgressDialog; 
    FinalAdapter adapter; 
    List<CodeList> codelist = null; 
    SharedPreference shrdPreference; 
    boolean loadingMore = false; 
    private int limit = 20; 



    @Override 
    public void onCreate(Bundle savedInstanceState) 
    { 

     super.onCreate(savedInstanceState); 
     setContentView(R.layout.inter_layout); 
     shrdPreference = new SharedPreference(); 
     //Execute RemoteDataTask AsyncTask 
     new RemoteDataTask().execute(); 
    } 

    private class RemoteDataTask extends AsyncTask<Void, Void, Void> { 
     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 
      // Create a progressdialog 
      mProgressDialog = new ProgressDialog(InterActivity.this); 
      // Set progressdialog title 
      mProgressDialog.setTitle("Loading"); 
      // Set progressdialog message 
      mProgressDialog.setMessage("Please wait loading ..."); 
      mProgressDialog.setIndeterminate(false); 
      mProgressDialog.setCancelable(false); 
      // Show progressdialog 
      mProgressDialog.show(); 
     } 

     @Override 
     protected Void doInBackground(Void... params) { 
      //my own doinbackground() 
       } 
      } catch (ParseException e) { 
       Log.e("Error", e.getMessage()); 
       e.printStackTrace(); 
      } 
      return null; 
     } 

     @Override 
     protected void onPostExecute(Void result) { 
      // Locate the listview in listview_main.xml 
      listview = (ListView) findViewById(R.id.inter_layoutListView); 
      // Pass the results into ListViewAdapter.java 
      adapter = new FinalAdapter(InterActivity.this, 
              codelist); 

      AlphaInAnimationAdapter animationAdapter = new AlphaInAnimationAdapter(adapter); 
      animationAdapter.setAbsListView(listview); 

      View loadMoreView = ((LayoutInflater)InterActivity.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE)) 
       .inflate(R.layout.loadmore, null, false); 

      listview.addFooterView(loadMoreView); 

      // Binds the Adapter to the ListView 
      listview.setAdapter(adapter); 

      listview.setOnItemClickListener(InterActivity.this); 

      listview.setOnItemLongClickListener(InterActivity.this); 
      // Close the progressdialog 
      mProgressDialog.dismiss(); 

      listview.setOnScrollListener(new OnScrollListener(){ 

    @Override 
     public void onScrollStateChanged(AbsListView view, int scrollState) {} 

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

     int lastInScreen = firstVisibleItem + visibleItemCount;  
    if((lastInScreen == totalItemCount) && !(loadingMore)){  

     new LoadMoreDataTask().execute(); 
     } 
     } 
     }); 

     } 
    } 
    private class LoadMoreDataTask extends AsyncTask<Void, Void, Void> { 
     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 



      } 

     @Override 
     protected Void doInBackground(Void... params) { 
      // my own doinbackground() 
     } 

     @Override 
     protected void onPostExecute(Void result) { 
      // Locate listview last item 
      int position = listview.getLastVisiblePosition(); 
      // Pass the results into ListViewAdapter.java 
      adapter = new FinalAdapter(InterActivity.this, codelist); 
      // Binds the Adapter to the ListView 
      listview.setAdapter(adapter); 
      // Show the latest retrived results on the top 
      listview.setSelectionFromTop(position, 0); 


     } 

    } 

Answer 1

更改onScroll()到

if (!loadingMore && lastInScreen >= totalItemCount && totalItemCount > 0) 
    new LoadMoreDataTask().execute();