列表未使用onscroll侦听器加载

Question

我有一个列表视图，可以从parse.com检索数据。在用户达到每15个项目后，我添加了一个onscroll侦听器来加载新的列表项。当用户滚动执行前15的结束时，从那时开始显示加载页脚，但是没有显示下一个列表项。不知道问题是什么？ 请帮帮我

我的代码

public class InterActivity extends Activity implements OnItemClickListener, OnItemLongClickListener, 
 AbsListView.OnScrollListener


 {


ListView listview;
List<ParseObject> ob;
ProgressDialog mProgressDialog;
FinalAdapter adapter;
 List<CodeList> codelist = null;
 SharedPreference shrdPreference;

 private int limit = 15;

 private final int AUTOLOAD_THRESHOLD = 4; 
 private final int MAXIMUM_ITEMS = 52;

 private View mFooterView;
 private Handler mHandler;
 private boolean mIsLoading = false;
 private boolean mMoreDataAvailable = true;
 private boolean mWasLoading = false;

View footerView;

private Runnable mAddItemsRunnable = new Runnable() { 
@Override public void run() { 

new Loadmore().execute();
mIsLoading = false;
    }
    };


@Override
public void onCreate(Bundle savedInstanceState)
{

    super.onCreate(savedInstanceState);
    setContentView(R.layout.inter_layout);
    shrdPreference = new SharedPreference();

    footerView = ((LayoutInflater) getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.loadmore, null, false);

    //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) {
        // Create the array
        codelist = new ArrayList<CodeList>();
        try {
            // Locate the class table named "Country" in Parse.com
            ParseQuery<ParseObject> query = new ParseQuery<ParseObject>(
                "InterActivity");
            // Locate the column named "ranknum" in Parse.com and order list
            // by ascending
            query.orderByAscending("_created_at");
            query.setLimit(limit);
            ob = query.find();
            for (ParseObject inter : ob) {


                map.setIntroduction((String) inter.get("intro"));
                map.setFinalCodeText((String) inter.get("codetext"));


                codelist.add(map);
            }
        } 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);

        mHandler = new Handler(); 
        mFooterView = LayoutInflater.from(InterActivity.this).inflate(R.layout.loadmore, null);
        listview.addFooterView(mFooterView, null, false);

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

        listview.setOnItemClickListener(InterActivity.this);

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




    }
}

@Override 
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
    if(!mIsLoading && mMoreDataAvailable) { 
    if (totalItemCount >= MAXIMUM_ITEMS) {
        mMoreDataAvailable = false;
        listview.removeFooterView(mFooterView);
    } else if (totalItemCount - AUTOLOAD_THRESHOLD <= firstVisibleItem + visibleItemCount) {
        mIsLoading = true; 
        mHandler.postDelayed(mAddItemsRunnable, 1000); 
        } 
    }
}


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

@Override
public void onStart() {
    super.onStart(); if (mWasLoading) {
        mWasLoading = false; mIsLoading = true;
        mHandler.postDelayed(mAddItemsRunnable, 1000); 
        } 
    }


@Override 
public void onStop() { 
super.onStop(); 
mHandler.removeCallbacks(mAddItemsRunnable); 
mWasLoading = mIsLoading;
mIsLoading = false; 
}

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

    }

    @Override
    protected Void doInBackground(Void... params) {
        // Create the array
        codelist = new ArrayList<CodeList>();
        try {
            // Locate the class table named "Country" in Parse.com
            ParseQuery<ParseObject> query = new ParseQuery<ParseObject>(
                "InterActivity");
            // Locate the column named "ranknum" in Parse.com and order list
            // by ascending
            query.orderByAscending("_created_at");
            query.setLimit(limit += 15);
            ob = query.find();
            for (ParseObject inter : ob) {



                map.setIntroduction((String) inter.get("intro"));
                map.setFinalCodeText((String) inter.get("codetext"));


                codelist.add(map);
            }
        } catch (ParseException e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        int position = listview.getLastVisiblePosition();
        adapter = new FinalAdapter(InterActivity.this,
                                   codelist);

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


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

        listview.setSelectionFromTop(position, 0);
    }
}