Android中的分页加载

//----------------------MainActivity中---------------------------------------------------

package com.example.fenye;

import java.util.ArrayList;
import java.util.List;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {
   //每次加载的数量
   private final int PAGE_NUMBER=15;
   //index第几条目
   private int index=0;

   private List<String> list=new ArrayList<String>();

    private ListView listview;
   private MyAdapter adapter;

   @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //找到控件Listview
        listview = (ListView) findViewById(R.id.listview);

        //设置Listview的滚动监听
        listview.setOnScrollListener(new OnScrollListener() {

           @Override
           public void onScrollStateChanged(AbsListView view, int scrollState) {
               //判断如果滚动停止时
               if (scrollState==OnScrollListener.SCROLL_STATE_IDLE) {
                   //如果滚到到了最下面一行
                   if (view.getLastVisiblePosition()==list.size()-1) {
                       //从新赋值
                       index=index+PAGE_NUMBER;
                       //吐司提醒
                       Toast.makeText(MainActivity.this, "加载中...", 0).show();
                       //重新加载数据
                       getData();
                   }
               }

           }

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


           }
       });

        //加载数据
        getData();

    }

   //加载数据
    private void getData() {
       new Thread(){
           public void run() {
               //index第几条目
               for (int i = index; i < index+PAGE_NUMBER; i++) {
                   list.add("我是条目"+i);
               }
           };
       }.start();

       //每次加载的数量
       try {
           //延迟1秒
           Thread.sleep(1000);
       } catch (InterruptedException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
       //若果适配器为空，就创建适配器
       if (adapter==null) {
           adapter = new MyAdapter(list, this);
            listview.setAdapter(adapter);
       }else{
           //刷新适配器
           adapter.notifyDataSetChanged();
       }

   }



}

//------------------------main.xml布局文件中-----------------------------

//-------------------适配器----创建一个类继承----BaseAdapter---------------------------------------------

package com.example.fenye;

import java.util.List;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class MyAdapter extends BaseAdapter{
   private List<String> list;
   private Context context;


   public MyAdapter(List<String> list, Context context) {
       super();
       this.list = list;
       this.context = context;
   }

   @Override
   public int getCount() {
       // TODO Auto-generated method stub
       return list.size();
   }

   @Override
   public Object getItem(int position) {
       // TODO Auto-generated method stub
       return list.get(position);
   }

   @Override
   public long getItemId(int position) {
       // TODO Auto-generated method stub
       return position;
   }

   @Override
   public View getView(int position, View convertView, ViewGroup parent) {
       if (convertView==null) {
           convertView=View.inflate(context, R.layout.list_item, null);

       }
       TextView tv_name=(TextView) convertView.findViewById(R.id.tv_name);
       tv_name.setText(list.get(position));

       return convertView;
   }

}

//-----------------list_item.xml布局文件中-----------------------------------------

//================以上是自动加载===========================================

//==============下面做一下手动加载=====只需要在=onCreate的方法中修改一下，如下：=================

/*
* 手动加载在Listview中用到listview.addFooterView(view)，把button添加到Listview的最下面，
* 点击时，重新赋值和重新加载数据
*/

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

//找到控件Listview
listview = (ListView) findViewById(R.id.listview);

        //找到button的布局
        View view=getLayoutInflater().inflate(R.layout.button_footer, null);
        //把控件button添加到Listview的下面
        listview.addFooterView(view);
        Button button=(Button) view.findViewById(R.id.button);

        //加载数据
        getData();
        button.setOnClickListener(new OnClickListener() {

           @Override
           public void onClick(View v) {
               //重新赋值
               index=index+PAGE_NUMBER;
               //吐司提示
               Toast.makeText(MainActivity.this, "加载中...", 0).show();
               //加载数据
               getData();

           }
       });

    }

//---------------button_footer.xml布局文件中------------------