listView实现分页加载数据

当数据量较大时，一下子全部加载完，会出现卡顿现象，listview的分页加载可以解决这个问题。

MainActivity.java:

package com.example.datapageload;

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

import com.example.service.DataService;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AbsListView;
import android.widget.ArrayAdapter;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListView;

public class MainActivity extends ActionBarActivity {

	private ListView listView;
	List<String> data = new ArrayList<String>();
	ArrayAdapter<String> arrayAdapter;
	View v;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		listView = (ListView) this.findViewById(R.id.listView);
		data.addAll(DataService.getData(0, 20));
		
		v = getLayoutInflater().inflate(R.layout.footer, null);
		listView.setOnScrollListener(new ScrollListener());
		
		arrayAdapter = new ArrayAdapter<String>(this, R.layout.listview_item, 
				R.id.textView, data);
		listView.addFooterView(v);//必须放在setAdapter前面
		listView.setAdapter(arrayAdapter);
		listView.removeFooterView(v);
	}
	
	private int num = 20;//每页获取的条数
	private int maxpage = 5;//总共的页数
	private boolean loadfinish = true;
	private final class ScrollListener implements OnScrollListener{

		@Override
		public void onScrollStateChanged(AbsListView view, int scrollState) {
			Log.i("MainActivity", "scrollState="+scrollState);
		}

		@Override
		public void onScroll(AbsListView view, int firstVisibleItem,
				int visibleItemCount, int totalItemCount) {
			Log.i("MainActivity", "firstVisibleItem="+firstVisibleItem+"visibleItemCount="+visibleItemCount+"totalItemCount="+totalItemCount);
		    final int loadtotal = totalItemCount;
			int lastItemId = listView.getLastVisiblePosition();//获得当前屏幕的最后一个id
		    if((lastItemId+1) == totalItemCount){
		    	if(totalItemCount>0){
		    		int currentPage = totalItemCount%num==0?totalItemCount/num:totalItemCount/num+1;
			    	int nextPage = currentPage+1;//获取下一页
			    	if(nextPage<=maxpage && loadfinish){
			    		loadfinish = false;
			    		listView.addFooterView(v);
			    		new Thread(new Runnable() {
							
							@Override
							public void run() {
								try {
									Thread.sleep(3000);
								} catch (InterruptedException e) {
									// TODO Auto-generated catch block
									e.printStackTrace();
								}
								List<String> result = DataService.getData(loadtotal, loadtotal+num);
								//因为子线程不能够更改主线程控件,通过handler能传递消息
								handler.sendMessage(handler.obtainMessage(10, result));
							}
						}).start();
			    	}
		    	}
		    }
		}
	}
	Handler handler = new Handler(){
		public void handleMessage(Message msg) {
			data.addAll((List<String>) msg.obj);
		//	arrayAdapter.notifyDataSetChanged();//通过listview数据已经发生了改变，你需要进行界面的更改
			arrayAdapter.setNotifyOnChange(true);
			if(listView.getFooterViewsCount()>0)listView.removeFooterView(v);
			loadfinish = true;
		};
	};
}

实现屏幕页脚加载图标:

footer.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    
    <ProgressBar 
        android:id="@+id/c81_forthBar"
        android:layout_width="50dp"
        android:layout_height="wrap_content"
        style="?android:attr/progressBarStyle"
        />
    <TextView 
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center_vertical"
        android:textSize="20sp"
        android:text="数据正在加载..."
        />

</LinearLayout>

DataService:

package com.example.service;

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

public class DataService {

	public static List<String> getData(int offset, int maxResult){//分页
		List<String> data = new ArrayList<String>();
		for(int i=offset;i<maxResult;i++){
			data.add("ListView的分页加载"+i);
		}
		return data;
	}
}