android 滑动加载数据

package com.ScrollListView;

import android.app.ListActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.AbsListView.OnScrollListener;

public class EndLessActivity extends ListActivity implements OnScrollListener  { 
       
    Aleph0 adapter = new Aleph0(); 
    int mProgressStatus = 0;
    ProgressBar progressBar;
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        LinearLayout searchLayout = new LinearLayout(this);
        searchLayout.setOrientation(LinearLayout.HORIZONTAL);
              progressBar = new ProgressBar(this);
              progressBar.setPadding(0, 0, 15, 0);
              searchLayout.addView(progressBar,new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.WRAP_CONTENT,
                LinearLayout.LayoutParams.WRAP_CONTENT
              ));
              TextView textView = new TextView(this);
              textView.setText("加载中...");
              textView.setGravity(Gravity.CENTER_VERTICAL);
              searchLayout.addView(textView,new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.FILL_PARENT,
                LinearLayout.LayoutParams.FILL_PARENT
              ));
              searchLayout.setGravity(Gravity.CENTER);
              LinearLayout loadingLayout = new LinearLayout(this);
              loadingLayout.addView(searchLayout,new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.WRAP_CONTENT,
                LinearLayout.LayoutParams.WRAP_CONTENT
              ));
              loadingLayout.setGravity(Gravity.CENTER);
             getListView().addFooterView(loadingLayout);

        setListAdapter(adapter);  
        getListView().setOnScrollListener(this); 
    } 
 
    public void onScroll(AbsListView view, 
        int firstVisible, int visibleCount, int totalCount) { 
 
        boolean loadMore = /* maybe add a padding */ 
            firstVisible + visibleCount >= totalCount; 
 
        if(loadMore) { 
            adapter.count += visibleCount; // or any other amount 
            adapter.notifyDataSetChanged(); 
        } 
    } 
 
    public void onScrollStateChanged(AbsListView v, int s) { }     
 
    class Aleph0 extends BaseAdapter { 
        int count = 40; /* starting amount */ 
 
        public int getCount() { return count; } 
        public Object getItem(int pos) { return pos; } 
        public long getItemId(int pos) { return pos; } 
 
        public View getView(int pos, View v, ViewGroup p) { 
                TextView view = new TextView(EndLessActivity.this); 
                view.setText("entry " + pos); 
                return view; 
        } 
    } 



}

 listview下部是按钮控制：

package com.ScrollListView;

import android.app.ListActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.AbsListView.OnScrollListener;

public class EndLessActivity extends ListActivity   { 
       
    Aleph0 adapter = new Aleph0(); 
    int mProgressStatus = 0;
    
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        LinearLayout searchLayout = new LinearLayout(this);
        searchLayout.setOrientation(LinearLayout.HORIZONTAL);
             
              Button textView = new Button(this);
              textView.setText("加载中...");
              textView.setGravity(Gravity.CENTER_VERTICAL);
              searchLayout.addView(textView,new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.FILL_PARENT,
                LinearLayout.LayoutParams.FILL_PARENT
              ));
              searchLayout.setGravity(Gravity.CENTER);
              LinearLayout loadingLayout = new LinearLayout(this);
              loadingLayout.addView(searchLayout,new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.WRAP_CONTENT,
                LinearLayout.LayoutParams.WRAP_CONTENT
              ));
              loadingLayout.setGravity(Gravity.CENTER);
             getListView().addFooterView(loadingLayout);
             textView.setOnClickListener(new Button.OnClickListener()   
             {        @Override      
                 public void onClick(View v)  
             {         
                 adapter.count += 10;  
                 adapter.notifyDataSetChanged(); 
                 }      
             });  
             
             
        setListAdapter(adapter);  
        //getListView().setOnScrollListener(this); 
    } 
 
  /*public void onScroll(AbsListView view, 
        int firstVisible, int visibleCount, int totalCount) { 
 
        boolean loadMore =  
            firstVisible + visibleCount >= totalCount; 
 
        if(loadMore) { 
            adapter.count += visibleCount;  
            adapter.notifyDataSetChanged(); 
        } 
    } */
 
    public void onScrollStateChanged(AbsListView v, int s) { }     
 
    class Aleph0 extends BaseAdapter { 
        int count = 40; /* starting amount */ 
 
        public int getCount() { return count; } 
        public Object getItem(int pos) { return pos; } 
        public long getItemId(int pos) { return pos; } 
 
        public View getView(int pos, View v, ViewGroup p) { 
                TextView view = new TextView(EndLessActivity.this); 
                view.setText("entry " + pos); 
                return view; 
        } 
    } 



}