Android--ListView下拉刷新

整理了下以前写的小项目，ListView的下拉刷新，虽然小但还是想纪念下。。适合新手看，大神略过。。。

效果图：

   

代码：  实体类

package com.example.listviewrefreshdemo;
/**
 * @author 超超boy
 */
public class ApkEntity {
	private String name;
	private String des;
	private String info;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getDes() {
		return des;
	}
	public void setDes(String des) {
		this.des = des;
	}
	public String getInfo() {
		return info;
	}
	public void setInfo(String info) {
		this.info = info;
	}
	
}

 MainActivity：

package com.example.listviewrefreshdemo;

import java.util.ArrayList;

import com.example.listviewrefreshdemo.RefreshListView.IReflashListener;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
/**
 * @author 超超boy
 */
public class MainActivity extends Activity implements IReflashListener{
	ArrayList<ApkEntity> apk_list;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		setData();
		showList(apk_list);
	}

	MyAdapter adapter;
	RefreshListView listview;
	private void showList(ArrayList<ApkEntity> apk_list) {
		if (adapter == null) {
			listview = (RefreshListView) findViewById(R.id.listview);
			listview.setIReflashListener(this);
			adapter = new MyAdapter(this, apk_list);
			listview.setAdapter(adapter);
		} else {
			adapter.onDateChange(apk_list);
		}
	}

	private void setData() {
		apk_list = new ArrayList<ApkEntity>();
		for (int i = 0; i < 10; i++) {
			ApkEntity entity = new ApkEntity();
			entity.setName("默认数据");
			entity.setDes("这是一个神奇的应用");
			entity.setInfo("50w用户");
			apk_list.add(entity);
		}
	}

	private void setReflashData() {
		
		for (int i = 0; i < 2; i++) {
			ApkEntity entity = new ApkEntity();
			entity.setName("刷新数据");
			entity.setDes("这是一个神奇的应用");
			entity.setInfo("50w用户");
			apk_list.add(i,entity);
		}
	}
	@Override
	public void onReflash() {
		// TODO Auto-generated method stub
		Handler handler = new Handler();
		handler.postDelayed(new Runnable() {
			
			@Override
			public void run() {
				// TODO Auto-generated method stub
				//获取最新数据
				setReflashData();
				//通知界面显示
				showList(apk_list);
				//通知listview 刷新数据完毕；
				listview.reflashComplete();
			}
		}, 2000);
		
	}

	/**
	 * 回掉方法
	 */
	/*public void onReflash() {
		//获取最新数据
		setReflashData();
		//通知界面显示
		showList(apk_list);
		//通知listview刷新数据完毕
		listview.reflashComplete();
	}*/
}

　　RefreshListView：

package com.example.listviewrefreshdemo;

import java.text.SimpleDateFormat;
import java.util.Date;

import android.R.anim;
import android.R.interpolator;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.RotateAnimation;
import android.widget.AbsListView;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ProgressBar;
import android.widget.TextView;
/**
 * @author 超超boy
 */
public class RefreshListView extends ListView implements OnScrollListener{

	LayoutInflater inflater;
	View header;
	int headerHeight;   //顶部布局文件的高度
	int firstVisibleItem; //当前第一个可见的item的位置
	int scrollState;   //listview当前滚动状态
	boolean isRemark;  //标记，当前是在listview的最顶部摁下的
	int startY;   //摁下时的Y值
	int state;  //当前的状态
	final int NONE = 0;// 正常状态；
	final int PULL = 1;// 提示下拉状态；
	final int RELESE = 2;// 提示释放状态；
	final int REFLASHING = 3;// 刷新状态；
	
	IReflashListener reflashListener;
	public RefreshListView(Context context) {
		super(context);
		initView(context);
	}

	public RefreshListView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		initView(context);
	}

	public RefreshListView(Context context, AttributeSet attrs) {
		super(context, attrs);
		initView(context);
	}
    /**
     * 初始化界面，添加顶部布局文件到ListView
     * @param context
     */
	private void initView(Context context){
		inflater = LayoutInflater.from(context);
		header  =inflater.inflate(R.layout.header, null);
		measureView(header);
		headerHeight = header.getMeasuredHeight();
		Log.i("tag", "headerHeight="+headerHeight);
		topPadding(-headerHeight);  //负的高度，把它能没啦
		this.addHeaderView(header);
	    this.setOnScrollListener(this);
	}
	/**
	 * 通知父布局，占用的宽高。
	 * @param view
	 */
	private void measureView(View view){
	  ViewGroup.LayoutParams p = view.getLayoutParams();
	  if(p == null){
		  p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
	  }
	  //spec:header的左右边距，padding内边距，childDimension字布局的宽度
	  int width = ViewGroup.getChildMeasureSpec(0, 0, p.width);
	  int height;
	  int tempHeight = p.height;
	  if(tempHeight > 0){ //高度不是空，需要填充这个布局
		  //EXACTLY(完全)，父元素决定自元素的确切大小，子元素将被限定在给定的边界里而忽略它本身大小；
		  height = MeasureSpec.makeMeasureSpec(tempHeight, MeasureSpec.EXACTLY);
	  }else{
		  //UNSPECIFIED(未指定),父元素不对子元素施加任何束缚，子元素可以得到任意想要的大小；
		  height = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
	  }
	  view.measure(width, height);
	}
	/**
	 * 设置header布局的上边距
	 * @param topPadding
	 */
	private void topPadding(int topPadding){ //header的上边距
		header.setPadding(header.getPaddingLeft(), topPadding, header.getPaddingRight(), header.getPaddingBottom());
		header.invalidate();
	}

    /**
     * 取得当前的滚动状态
     */
	public void onScrollStateChanged(AbsListView view, int scrollState) {
		
		this.scrollState = scrollState; 
	}

	@Override
	public void onScroll(AbsListView view, int firstVisibleItem,
			int visibleItemCount, int totalItemCount) {
		this.firstVisibleItem = firstVisibleItem;  //当前第一个可见的item的位置
		
	}
	
    /**
     * 触摸事件
     */
	public boolean onTouchEvent(MotionEvent ev) {
		switch (ev.getAction()) {
		case MotionEvent.ACTION_DOWN:  //下拉
			if (firstVisibleItem == 0) { //在界面最顶端
				isRemark = true;     //标记，当前是在listview的最顶部摁下的 
				startY = (int) ev.getY();
			}
			break;

		case MotionEvent.ACTION_MOVE:
			 onMove(ev);
			 break;
		case MotionEvent.ACTION_UP:  //抬起
			if (state == RELESE) {  //释放
				state = REFLASHING; //正在刷新
				// 加载最新数据；
				reflashViewByState();
				reflashListener.onReflash();
			} else if (state == PULL) {  //下拉过程中，没到一定距离的时候
				state = NONE;  // 正常状态；
				isRemark = false;   //在顶部的标记
				reflashViewByState();
			}
			break;
		}
		return super.onTouchEvent(ev);
	}
	/**
	 * 判断移动过程的操作
	 * @param ev
	 */
	private void onMove(MotionEvent ev) {
		if(!isRemark){  //不在顶的时候移动
			return;
		}
		//移动的过程中状态是不断改变的
		int tempY = (int) ev.getY();
		int sapce = tempY-startY;  //移动的距离
		int topPadding = sapce - headerHeight; //移动过程中不断设置topPadding
		switch (state) {
		case NONE:   // 正常状态；
			if(sapce>0){
				state = PULL; // 提示下拉状态
				reflashViewByState();
			}
			break;
        case PULL:   // 提示下拉状态；
        	topPadding(topPadding);  //不断设置上边距
        	if(sapce > headerHeight+30 
        			&& scrollState == SCROLL_STATE_TOUCH_SCROLL){
				state = RELESE;  // 提示释放状态；
				reflashViewByState();
			}
			
			break;
        case RELESE:    // 提示释放状态；
        	topPadding(topPadding);
        	if(sapce<headerHeight+30){
				state = PULL;
				reflashViewByState();
			}else if(sapce <= 0){
				state = NONE;
				isRemark = false;
				reflashViewByState();
			}
	     break;
		default:
			break;
		}
		
	}
	/**
	 * 根据当前的状态，改变页面显示
	 */
	private void reflashViewByState(){
		TextView tip = (TextView) header.findViewById(R.id.tip);
		ImageView arrow = (ImageView) header.findViewById(R.id.arrow);
		ProgressBar bar = (ProgressBar) header.findViewById(R.id.progress);
		RotateAnimation animation = new RotateAnimation(0, 180
				,RotateAnimation.RELATIVE_TO_SELF,0.5f,
				RotateAnimation.RELATIVE_TO_SELF,0.5f);
		animation.setDuration(500);
		animation.setFillAfter(true);
		RotateAnimation animation2 = new RotateAnimation(180, 0
				,RotateAnimation.RELATIVE_TO_SELF,0.5f,
				RotateAnimation.RELATIVE_TO_SELF,0.5f);
		animation2.setDuration(500);
		animation2.setFillAfter(true);
		switch (state) {
		case NONE:
			arrow.clearAnimation();
            topPadding(-headerHeight);
			break;
		case PULL:     //下拉
			arrow.setVisibility(View.VISIBLE);
			bar.setVisibility(View.GONE);
			tip.setText("下拉可以刷新");
			arrow.clearAnimation();
			arrow.setAnimation(animation2);
			break;
		case RELESE:    //释放
			arrow.setVisibility(View.VISIBLE);
			bar.setVisibility(View.GONE);
			tip.setText("松开可以刷新");
			arrow.clearAnimation();
			arrow.setAnimation(animation);
			break;
		case REFLASHING:  //刷新
			topPadding(50);
			arrow.setVisibility(View.GONE);
			bar.setVisibility(View.VISIBLE);
			tip.setText("正在刷新");
			arrow.clearAnimation();
			break;

		default:
			break;
		}
	}
	/**
	 * 获取完数据
	 */
	public void reflashComplete(){
	   state = NONE;
	   isRemark = false;  //不在顶部
	   reflashViewByState();
	   TextView lastupdatetime = (TextView) header.findViewById(R.id.lastUpdate_time);
	   SimpleDateFormat format = new SimpleDateFormat("yyyy年MM月dd日 hh:mm:ss");
	   Date date = new Date(System.currentTimeMillis());
	   String time = format.format(date);
	   lastupdatetime.setText(time);
	   
	}
	/**
	 * 回调接口
	 * @author user
	 *
	 */
	public interface IReflashListener{
		public void onReflash();
	}
	public void setIReflashListener(IReflashListener listener){
		this.reflashListener = listener;
	}
}

　　适配器:

package com.example.listviewrefreshdemo;

import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
/**
 * @author 超超boy
 */
public class MyAdapter extends BaseAdapter {
	ArrayList<ApkEntity> apk_list;
	LayoutInflater inflater;

	public MyAdapter(Context context, ArrayList<ApkEntity> apk_list) {
		this.apk_list = apk_list;
		this.inflater = LayoutInflater.from(context);
	}

	public void onDateChange(ArrayList<ApkEntity> apk_list) {
		this.apk_list = apk_list;
		this.notifyDataSetChanged(); //更新数据
	}

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

	@Override
	public Object getItem(int position) {
		// TODO Auto-generated method stub
		return apk_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) {
		// TODO Auto-generated method stub
		ApkEntity entity = apk_list.get(position);
		ViewHolder holder;
		if (convertView == null) {
			holder = new ViewHolder();
			convertView = inflater.inflate(R.layout.item_layout, null);
			holder.name_tv = (TextView) convertView
					.findViewById(R.id.item3_apkname);
			holder.des_tv = (TextView) convertView
					.findViewById(R.id.item3_apkdes);
			holder.info_tv = (TextView) convertView
					.findViewById(R.id.item3_apkinfo);
			convertView.setTag(holder);
		}else{
			holder = (ViewHolder) convertView.getTag();
		}
		holder.name_tv.setText(entity.getName());
		holder.des_tv.setText(entity.getDes());
		holder.info_tv.setText(entity.getInfo());
		return convertView;
	}

	class ViewHolder {
		TextView name_tv;
		TextView des_tv;
		TextView info_tv;
	}
}

　　activity_main.xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.listviewrefreshdemo.MainActivity" >

    <com.example.listviewrefreshdemo.RefreshListView
        android:id="@+id/listview"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:background="@color/white"
        android:cacheColorHint="#00000000"
        android:dividerHeight="5dip" />

</RelativeLayout>

　　布局文件还有header.xml和item_layout.xml，就不粘贴了，想看的可以去下我的源代码，下边有下载链接。。

二、代码逻辑

    1.自定义状态：PULL下拉状态，RELESE释放状态，REFLASHING刷新状态

    2. AbsListView的触摸事件：

      下拉的时候设置startY(开始滑动时的位置)，之后就是不断的滑动过程，滑动的过程中，用自定义的onMove方法改变状态和header界面（下拉刷新，释放刷新，刷新中）；

       刷新：

       case MotionEvent.ACTION_UP: //抬起
       if (state == RELESE) { //释放
         state = REFLASHING; //正在刷新
        reflashViewByState();// 加载最新数据；

         reflashListener.onReflash(); //在回调接口刷新  }

    3.自定义的move时判断状态信息：

    下拉->释放：sapce > headerHeight+30 判断距离，距离够了就改变状态：释放状态，释放更新

	int sapce = tempY-startY;  //移动的距离
	int topPadding = sapce - headerHeight; //移动过程中不断设置topPadding
		switch (state) {
		case NONE:   // 正常状态；
			if(sapce>0){
				state = PULL; // 提示下拉状态
				reflashViewByState();
			}
			break;
        case PULL:   // 提示下拉状态；
        	topPadding(topPadding);  //不断设置上边距
        	if(sapce > headerHeight+30 
        			&& scrollState == SCROLL_STATE_TOUCH_SCROLL){
				state = RELESE;  // 提示释放状态；
				reflashViewByState();
			}
			
			break;
        case RELESE:    // 提示释放状态；
        	topPadding(topPadding);
        	if(sapce<headerHeight+30){
				state = PULL;
				reflashViewByState();
			}else if(sapce <= 0){
				state = NONE;
				isRemark = false;
				reflashViewByState();
			}
	     break;

 

　　  ok。。代码很简单。。。

Demo源代码下载：http://download.csdn.net/detail/jycboy/9588195

附一篇很好的博文：Android 下拉刷新框架实现：http://blog.csdn.net/leehong2005/article/details/12567757

 转发请注明出处：http://www.cnblogs.com/jycboy/p/5712620.html