ListView下拉刷新（慕课网教材源码）

MainActivity

package com.imooc.listviewfrashdemo1;

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;

import com.example.listviewfrashdemo1.R;
import com.imooc.listviewfrashdemo1.ReFlashListView.IReflashListener;

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;
ReFlashListView listview;
private void showList(ArrayList<ApkEntity> apk_list) {
if (adapter == null) {
listview = (ReFlashListView) findViewById(R.id.listview);
listview.setInterface(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("Ĭ������");
entity.setDes("����һ�������Ӧ��");
entity.setInfo("50w�û�");
apk_list.add(entity);
}
}

private void setReflashData() {
for (int i = 0; i < 2; i++) {
ApkEntity entity = new ApkEntity();
entity.setName("ˢ������");
entity.setDes("����һ�������Ӧ��");
entity.setInfo("50w�û�");
apk_list.add(0,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
//��ȡ��������
setReflashData();
//֪ͨ������ʾ
showList(apk_list);
//֪ͨlistview ˢ��������ϣ�
listview.reflashComplete();
}
}, 2000);

}
}

ApkEntity.class

package com.imooc.listviewfrashdemo1;

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;
}

}

MyAdapter.class

package com.imooc.listviewfrashdemo1;

import java.util.ArrayList;

import com.example.listviewfrashdemo1.R;

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

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();
}

@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;
}
}

ReFlashListView.class

package com.imooc.listviewfrashdemo1;

import com.example.listviewfrashdemo1.R;

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.MeasureSpec;
import android.view.ViewGroup;
import android.view.animation.RotateAnimation;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;

public class ReFlashListView extends ListView implements OnScrollListener {

private View header;
private int headerHeight;// 顶部布局文件的高度
private int firstVisibleItem;// 当前第一个可见的item的位置
private int scrollStste;// listview 当前滚动状态

private boolean isRemark;// 标记，当前是在ListView的最顶端按下
private int startY;// 按下时的Y值

private int state;// 当前状态
private final int NONE = 0;// 正常状态
private final int PULL = 1;// 提示下拉状态
private final int RELSE = 2;// 提示释放状态
private final int REFLASHING = 3;// 刷新状态

private IReflashListener reflashListener;// 刷新数据的接口

public ReFlashListView(Context context) {
super(context);
initView(context);
}

public ReFlashListView(Context context, AttributeSet attrs) {
super(context, attrs);
initView(context);
}

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

/**
* 初始化界面，添加顶部布局文件到listview里面
*
* @param context
*/
private void initView(Context context) {
LayoutInflater inflater = LayoutInflater.from(context);
header = inflater.inflate(R.layout.header_layout, null);
measureView(header);
headerHeight = header.getMeasuredHeight();
topPadding(-headerHeight);
this.addHeaderView(header);
this.setOnScrollListener(this);
}

/**
* 通知父布局，占用多大地方
*
* @param v
*/
private void measureView(View v) {
ViewGroup.LayoutParams p = v.getLayoutParams();
if (p == null) {
p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
}
int width = ViewGroup.getChildMeasureSpec(0, 0, p.width);
int height;
int tempHeight = p.height;
if (tempHeight > 0) {
height = MeasureSpec.makeMeasureSpec(tempHeight,
MeasureSpec.EXACTLY);
} else {
height = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
}
v.measure(width, height);
}

/**
* 设置header布局的上边距
*
* @param topPadding
*/
private void topPadding(int topPadding) {
header.setPadding(header.getPaddingLeft(), topPadding,
header.getPaddingRight(), header.getPaddingBottom());
header.invalidate();
}

@Override
public void onScroll(AbsListView arg0, int firstVisibleItem, int arg2,
int arg3) {
this.firstVisibleItem = firstVisibleItem;
}

@Override
public void onScrollStateChanged(AbsListView arg0, int scrollStste) {
this.scrollStste = scrollStste;
}

@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
if (firstVisibleItem == 0) {
isRemark = true;
startY = (int) ev.getY();
}
break;
case MotionEvent.ACTION_MOVE:
onMove(ev);
break;

case MotionEvent.ACTION_UP:
if (state == RELSE) {
state = REFLASHING;
reflashViewByState();
// 加载最新数据
reflashListener.onReflash();
} else if (state == PULL) {
state = NONE;
isRemark = false;
reflashViewByState();
}
break;
}
return super.onTouchEvent(ev);
}

/**
* 判断移动过程中的操作
*
* @param ev
*/
private void onMove(MotionEvent ev) {
if (!isRemark) {
return;
}
int tempY = (int) ev.getY();
int space = tempY - startY;
int topPadding = space - headerHeight;
switch (state) {
case NONE:
// 下拉状态
if (space > 0) {
state = PULL;
reflashViewByState();
}
break;

case PULL:
topPadding(topPadding);
// 下拉达到一定程度，并且ListView当前是滚动状态
if (space > headerHeight + 30
&& scrollStste == SCROLL_STATE_TOUCH_SCROLL) {
state = RELSE;
reflashViewByState();
}
break;
case RELSE:
topPadding(topPadding);
if (space < headerHeight + 30) {
state = PULL;
reflashViewByState();
} else if (space <= 0) {
state = NONE;
isRemark = false;
reflashViewByState();
}
break;
}
}

/**
* 根据当前状态改变界面显示
*/
private void reflashViewByState() {
TextView tip = (TextView) header.findViewById(R.id.tip);
ImageView arrow = (ImageView) header.findViewById(R.id.arrow);
ProgressBar progress = (ProgressBar) header.findViewById(R.id.progress);

RotateAnimation anim = new RotateAnimation(0, 180,
RotateAnimation.RELATIVE_TO_SELF, 0.5f,
RotateAnimation.RELATIVE_TO_SELF, 0.5f);
anim.setDuration(500);
anim.setFillAfter(true);
RotateAnimation anim1 = new RotateAnimation(180, 0,
RotateAnimation.RELATIVE_TO_SELF, 0.5f,
RotateAnimation.RELATIVE_TO_SELF, 0.5f);
anim1.setDuration(500);
anim1.setFillAfter(true);

switch (state) {
case NONE:
topPadding(-headerHeight);
arrow.clearAnimation();
break;

case PULL:
arrow.setVisibility(View.VISIBLE);
progress.setVisibility(View.GONE);
tip.setText("下拉可以刷新");
arrow.clearAnimation();
arrow.setAnimation(anim1);
break;
case RELSE:
arrow.setVisibility(View.VISIBLE);
progress.setVisibility(View.GONE);
tip.setText("松开可以刷新");
arrow.clearAnimation();
arrow.setAnimation(anim);
break;
case REFLASHING:
arrow.clearAnimation();
topPadding(0);// 刷新的时候高度固定不变
arrow.setVisibility(View.GONE);
progress.setVisibility(View.VISIBLE);
tip.setText("正在刷新");
break;
}
}

/**
* 获取完数据
*/
public void reflashComplete() {
state = NONE;
isRemark = false;
reflashViewByState();
}

public void setInterface(IReflashListener reflashListener) {
this.reflashListener = reflashListener;
}

/**
* 刷新数据接口
*/
public interface IReflashListener {
public void onReflash();
}
}

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"
android:background="@color/white"
tools:context=".MainActivity" >

<com.imooc.listviewfrashdemo1.ReFlashListView
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>

header_layout.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="wrap_content"
android:orientation="vertical" >

<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingBottom="10dip"
android:paddingTop="10dip" >

<LinearLayout
android:id="@+id/layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:gravity="center"
android:orientation="vertical" >

<TextView
android:id="@+id/tip"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="下拉可以刷新！" />

<TextView
android:id="@+id/lastupdate_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>

<ImageView
android:id="@+id/arrow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toLeftOf="@id/layout"
android:layout_marginRight="20dip"
android:src="@drawable/pull_to_refresh_arrow" />

<ProgressBar
android:id="@+id/progress"
style="?android:attr/progressBarStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toLeftOf="@id/layout"
android:layout_marginRight="20dip"
android:visibility="gone" />
</RelativeLayout>

</LinearLayout>

item_layout.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" >

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="60dip"
android:gravity="center_vertical"
android:background="@drawable/app_item_bg"
android:orientation="horizontal" >

<ImageView
android:id="@+id/item3_apkiv"
android:layout_width="50dip"
android:layout_height="50dip"
android:background="@drawable/test_icon"
android:layout_marginLeft="10dip" />

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_marginLeft="10dip"
android:orientation="vertical" >

<TextView
android:id="@+id/item3_apkname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="应用程序名字"
android:textColor="@color/black"
android:textSize="18dip" />

<TextView
android:id="@+id/item3_apkinfo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dip"
android:text="应用程序信息"
android:textSize="14dip" />
</LinearLayout>
<Button
android:layout_width="60dip"
android:layout_height="30dip"
android:background="@drawable/dlbtn_selector"
android:id="@+id/item3_dlbtn"
android:layout_marginRight="10dip"
android:text="安装"
/>
</LinearLayout>

<TextView
android:id="@+id/item3_apkdes"
android:layout_width="fill_parent"
android:layout_height="30dip"
android:layout_marginLeft="5dip"
android:layout_marginRight="5dip"
android:gravity="center_vertical"
android:text="应用程序描述"
android:textSize="14dip" />

</LinearLayout>