ListView上下拉刷新

listview的上下拉刷新在大部分的app中都有用到，可以使用第三方的PullToRefresh框架也可以自定义listview控件。下面是自定义的listview类：

public class LoadListView extends ListView  implements OnScrollListener{
View footer;//底部布局
int totalItemCount;//总数量
int lastVisibleItem;//最后一个可见的item
boolean isLoading =false;//正在加载
ILoadListener iLoadListener;
View header;
int headerHeight;//顶部布局文件的高度
int firstVisibleItem;
boolean isRemark;//標記，當前實在listview 最頂端按下的。
int startY;//按下時的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
int scrollState;//當前滾動狀態
IReflashListener iReflashListener;//刷新數據的接口
public LoadListView(Context context) {
super(context);
initView(context);
}

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

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

/**
* 添加底部加载提示到ListView
* 添加顶部加载提示到ListView
* @param context
*/
private void initView(Context context){
//上拉加载
LayoutInflater inflater = LayoutInflater.from(context);
footer=inflater.inflate(R.layout.footer_layout,null);
footer.findViewById(R.id.txt).setVisibility(View.INVISIBLE);
this.setOnScrollListener(this);//设置滚动监听
this.addFooterView(footer);

//下拉刷新
header=inflater.inflate(R.layout.header_layout,null);
measureView(header);
headerHeight = header.getMeasuredHeight();
topPadding(-headerHeight);
this.addHeaderView(header);

}
//计算顶部占多大
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);//得到的是tempheight
}else{
height = MeasureSpec.makeMeasureSpec(0,MeasureSpec.UNSPECIFIED);//得到的是字布局的实际大小
}
v.measure(width, height);

}

public void topPadding(int topPadding){
header.setPadding(header.getPaddingLeft(),topPadding,header.getPaddingRight(),header.getPaddingBottom());
header.invalidate();
}
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
//DOTO 下拉中
this.lastVisibleItem=firstVisibleItem+visibleItemCount;
this.totalItemCount=totalItemCount;

this.firstVisibleItem=firstVisibleItem;
}

@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==RELESE){
state=REFLASHING;
reflashViewByState();
//加載最新數據
iReflashListener.onReflash();
}else if(state==PULL){
state=NONE;
isRemark=false;
reflashViewByState();
}
break;

default:
break;
}

return super.onTouchEvent(ev);

}

private void reflashViewByState(){

TextView tip = (TextView) header.findViewById(R.id.tip);
ImageView arrow = (ImageView) header.findViewById(R.id.imag);
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);
break;
case PULL:
arrow.setVisibility(View.VISIBLE);
progress.setVisibility(View.INVISIBLE);
tip.setText(getResources().getString(R.string.xialashuxin));
arrow.clearAnimation();
arrow.setAnimation(anim1);

break;
case RELESE:
arrow.setVisibility(View.VISIBLE);
progress.setVisibility(View.INVISIBL
10428
E);
tip.setText(getResources().getString(R.string.songkaishuxin));
arrow.clearAnimation();
arrow.setAnimation(anim);
break;
case REFLASHING:
topPadding(50);
arrow.setVisibility(View.INVISIBLE);
progress.setVisibility(View.VISIBLE);
tip.setText(getResources().getString(R.string.zenzaishuxin));
arrow.clearAnimation();
break;
default:
break;
}
}

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:
if(space>0){
state=PULL;
reflashViewByState();
}
break;
case PULL:
topPadding(topPadding);
if(space>headerHeight+30 && scrollState==SCROLL_STATE_TOUCH_SCROLL){
state=RELESE;
reflashViewByState();
}
break;
case RELESE:
topPadding(topPadding);
if(space<headerHeight+30){
state=PULL;
reflashViewByState();
}else if(space<0){
state=NONE;
isRemark=false;
reflashViewByState();
}
break;
case REFLASHING:

break;
default:
break;
}
}

/**
* 下拉刷新完成
*/
public void reflashComplete(){
state = NONE;
isRemark = false;
reflashViewByState();

TextView lastupdatetime = (TextView) header.findViewById(R.id.lasttime);
SimpleDateFormat format = new SimpleDateFormat("yyyy年MM月dd日");
Date date = new Date(System.currentTimeMillis());
String time = format.format(date);
lastupdatetime.setText(time);

}

public void setReflashInterface(IReflashListener iListener){
this.iReflashListener=iListener;
}

public interface IReflashListener{
public void onReflash();
}

public void onScrollStateChanged(AbsListView view, int scrollState) {
//DOTO 滑动状态改变
if(totalItemCount==lastVisibleItem && scrollState==SCROLL_STATE_IDLE){
footer.findViewById(R.id.txt).setVisibility(View.VISIBLE);
if(!isLoading){
isLoading=true;
//footer.findViewById(R.id.txt).setVisibility(View.VISIBLE);
//加载更多
iLoadListener.onLoad();
}
}

this.scrollState=scrollState;

}
public void setInterface(ILoadListener iLoadListener){
this.iLoadListener=iLoadListener;
}

public interface ILoadListener{
public void onLoad();
}

/**
* 上拉加載完成
*/
public void loadComplete(){
isLoading=false;
footer.findViewById(R.id.txt).setVisibility(View.INVISIBLE);
}
}

activity中的调用方法：

//activity实现上拉、下拉监听
public class Main extends Activity implements ILoadListener,IReflashListener {
private LoadListView list;
boolean isloading=false;
boolean isReflashing=false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
list = (LoadListView) findViewById(R.id.list);
//隐藏listview头布局
list.setHeaderDividersEnabled(false);
//隐藏listview底部布局
list.setFooterDividersEnabled(false);
//设置listview的上拉加载监听
list.setInterface(this);
//设置listview的下拉刷新监听
list.setReflashInterface(this);
}

public void onReflash() {
//更新listview数据
}
}
public void onLoad() {
//更新listview数据
}
}
}

顶部布局文件如下：

<?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" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="10dp"
android:paddingBottom="10dp"
>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_centerInParent="true"
android:id="@+id/layout"
android:gravity="center"
>
<TextView
android:id="@+id/tip"
android:text="@string/xialashuxin"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/lasttime"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
<ImageView
android:id="@+id/imag"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toLeftOf="@id/layout"
android:layout_marginRight="20dp"
android:src="@drawable/pull_to_refresh_arrow"
/>

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

</RelativeLayout>
</LinearLayout>

底部布局文件如下：

<LinearLayout 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:orientation="vertical"
>
<LinearLayout
android:id="@+id/txt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:paddingTop="10dp"
android:paddingBottom="10dp"
android:gravity="center"
>
<ProgressBar
android:layout_width="wrap_content"
android:layout_height="wrap_content"
style="?android:attr/progressBarStyleSmall"
/>
<!--  <TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="正在加载..."
/> -->

</LinearLayout>
</LinearLayout>