整理了下以前寫的小項目，ListView的下拉刷新，雖然小但還是想紀念下。。適合新手看，大神略過。。。
效果圖：
代碼： 實體類
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("默認數據");
entity.setDes("這是一個神奇的應用");
entity.setInfo("50w用戶");
apk_list.add(entity);
}
}
private void setReflashData() {
for (int i = 0; i < 2; i++) {
ApkEntity entity = new ApkEntity();
entity.setName("刷新數據");
entity.setDes("這是一個神奇的應用");
entity.setInfo("50w用戶");
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
//獲取最新數據
setReflashData();
//通知界面顯示
showList(apk_list);
//通知listview 刷新數據完畢；
listview.reflashComplete();
}
}, 2000);
}
/**
* 回掉方法
*/
/*public void onReflash() {
//獲取最新數據
setReflashData();
//通知界面顯示
showList(apk_list);
//通知listview刷新數據完畢
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; //頂部布局文件的高度
int firstVisibleItem; //當前第一個可見的item的位置
int scrollState; //listview當前滾動狀態
boolean isRemark; //標記，當前是在listview的最頂部摁下的
int startY; //摁下時的Y值
int state; //當前的狀態
final int NONE = 0;// 正常狀態；
final int PULL = 1;// 提示下拉狀態；
final int RELESE = 2;// 提示釋放狀態；
final int REFLASHING = 3;// 刷新狀態；
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，添加頂部布局文件到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); //負的高度，把它能沒啦
this.addHeaderView(header);
this.setOnScrollListener(this);
}
/**
* 通知父布局，占用的寬高。
* @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的左右邊距，padding內邊距，childDimension字布局的寬度
int width = ViewGroup.getChildMeasureSpec(0, 0, p.width);
int height;
int tempHeight = p.height;
if(tempHeight > 0){ //高度不是空，需要填充這個布局
//EXACTLY(完全)，父元素決定自元素的確切大小，子元素將被限定在給定的邊界里而忽略它本身大小；
height = MeasureSpec.makeMeasureSpec(tempHeight, MeasureSpec.EXACTLY);
}else{
//UNSPECIFIED(未指定),父元素不對子元素施加任何束縛，子元素可以得到任意想要的大小；
height = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
}
view.measure(width, height);
}
/**
* 設置header布局的上邊距
* @param topPadding
*/
private void topPadding(int topPadding){ //header的上邊距
header.setPadding(header.getPaddingLeft(), topPadding, header.getPaddingRight(), header.getPaddingBottom());
header.invalidate();
}
/**
* 取得當前的滾動狀態
*/
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; //當前第一個可見的item的位置
}
/**
* 觸摸事件
*/
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN: //下拉
if (firstVisibleItem == 0) { //在界面最頂端
isRemark = true; //標記，當前是在listview的最頂部摁下的
startY = (int) ev.getY();
}
break;
case MotionEvent.ACTION_MOVE:
onMove(ev);
break;
case MotionEvent.ACTION_UP: //抬起
if (state == RELESE) { //釋放
state = REFLASHING; //正在刷新
// 加載最新數據；
reflashViewByState();
reflashListener.onReflash();
} else if (state == PULL) { //下拉過程中，沒到一定距離的時候
state = NONE; // 正常狀態；
isRemark = false; //在頂部的標記
reflashViewByState();
}
break;
}
return super.onTouchEvent(ev);
}
/**
* 判斷移動過程的操作
* @param ev
*/
private void onMove(MotionEvent ev) {
if(!isRemark){ //不在頂的時候移動
return;
}
//移動的過程中狀態是不斷改變的
int tempY = (int) ev.getY();
int sapce = tempY-startY; //移動的距離
int topPadding = sapce - headerHeight; //移動過程中不斷設置topPadding
switch (state) {
case NONE: // 正常狀態；
if(sapce>0){
state = PULL; // 提示下拉狀態
reflashViewByState();
}
break;
case PULL: // 提示下拉狀態；
topPadding(topPadding); //不斷設置上邊距
if(sapce > headerHeight+30
&& scrollState == SCROLL_STATE_TOUCH_SCROLL){
state = RELESE; // 提示釋放狀態；
reflashViewByState();
}
break;
case RELESE: // 提示釋放狀態；
topPadding(topPadding);
if(sapce<headerHeight+30){
state = PULL;
reflashViewByState();
}else if(sapce <= 0){
state = NONE;
isRemark = false;
reflashViewByState();
}
break;
default:
break;
}
}
/**
* 根據當前的狀態，改變頁面顯示
*/
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: //釋放
arrow.setVisibility(View.VISIBLE);
bar.setVisibility(View.GONE);
tip.setText("松開可以刷新");
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;
}
}
/**
* 獲取完數據
*/
public void reflashComplete(){
state = NONE;
isRemark = false; //不在頂部
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);
}
/**
* 回調接口
* @author user
*
*/
public interface IReflashListener{
public void onReflash();
}
public void setIReflashListener(IReflashListener listener){
this.reflashListener = listener;
}
}
適配器:
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(); //更新數據
}
@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>
布局文件還有header.xml和item_layout.xml，就不粘貼了，想看的可以去下我的源代碼，下邊有下載鏈接。。
二、代碼邏輯
1.自定義狀態：PULL下拉狀態，RELESE釋放狀態，REFLASHING刷新狀態
2. AbsListView的觸摸事件：
下拉的時候設置startY(開始滑動時的位置)，之后就是不斷的滑動過程，滑動的過程中，用自定義的onMove方法改變狀態和header界面（下拉刷新，釋放刷新，刷新中）；
刷新：
case MotionEvent.ACTION_UP: //抬起
if (state == RELESE) { //釋放
state = REFLASHING; //正在刷新
reflashViewByState();// 加載最新數據；
reflashListener.onReflash(); //在回調接口刷新 }
3.自定義的move時判斷狀態信息：
下拉->釋放：sapce > headerHeight+30 判斷距離，距離夠了就改變狀態：釋放狀態，釋放更新
int sapce = tempY-startY; //移動的距離
int topPadding = sapce - headerHeight; //移動過程中不斷設置topPadding
switch (state) {
case NONE: // 正常狀態；
if(sapce>0){
state = PULL; // 提示下拉狀態
reflashViewByState();
}
break;
case PULL: // 提示下拉狀態；
topPadding(topPadding); //不斷設置上邊距
if(sapce > headerHeight+30
&& scrollState == SCROLL_STATE_TOUCH_SCROLL){
state = RELESE; // 提示釋放狀態；
reflashViewByState();
}
break;
case RELESE: // 提示釋放狀態；
topPadding(topPadding);
if(sapce<headerHeight+30){
state = PULL;
reflashViewByState();
}else if(sapce <= 0){
state = NONE;
isRemark = false;
reflashViewByState();
}
break;
ok。。代碼很簡單。。。
Demo源代碼下載：http://download.csdn.net/detail/jycboy/9588195
附一篇很好的博文：Android 下拉刷新框架實現：http://blog.csdn.net/leehong2005/article/details/12567757