listview下拉刷新上拉(滑动分页)加载更多

梦里梦外; 2022-08-18 05:54 226阅读 0赞

转自http://www.cnblogs.com/gzggyy/p/3154934.html

最 近做的类似于微博的项目中，有个Android功能要使用到listview的向下拉刷新来刷新最新消息，向上拉刷新（滑动分页）来加载更多。  
新浪微博就是使用这种方式的典型。  
当用户从网络上读取微博的时候，如果一下子全部加载用户未读的微博这将耗费比较长的时间，造成不好的用户体验，同时一屏的内容也不足以显示如此多的内容。这时候，我们就需要用到另一个功能，那就是listview的分页了，其实这个分页可以做成客户端的分页，也可以做成服务器端的分页（点击加载时，从服务器对应的加载第N页就好了！！！）。通过分页分次加载数据，用户看多少就去加载多少。  
通常这也分为两种方式，一种是设置一个按钮，用户点击即加载。另一种是当用户滑动到底部时自动加载。今天我就和大家分享一下滑动到底端时自动加载这个功能的实现。  
效果图如下所示：

![25162259-5fa5cedfdc6d4b8bb1134393218f3534.jpg][]

![25162321-14aaa3e697e64d1dadf5cc4ed5d3edcf.jpg][]

![25162338-601950593f10400d9dd761e044a24b74.jpg][]

下拉刷新最主要的流程是：  
(1). 下拉，显示提示头部界面(HeaderView)，这个过程提示用户”下拉刷新”  
(2). 下拉到一定程度，超出了刷新最基本的下拉界限，我们认为达到了刷新的条件，提示用户可以”松手刷新”了，效果上允许用户继续下拉  
(3). 用户松手，可能用户下拉远远不止提示头部界面，所以这一步，先反弹回仅显示提示头部界面，然后提示用户”正在加载”。  
(4). 加载完成后，隐藏提示头部界面。

那么让我们看看怎么才能实现呢？？？  
第一步：既然是要显示listview ，那么就应该有个listview 的容器pulldown.xml

![复制代码][copycode.gif]

<?xml version="1.0" encoding="utf-8"?>
 <com.solo.pulldown.PullDownView xmlns:android="http://schemas.android.com/apk/res/android"
 android:id="@+id/pull_down_view"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:background="@android:color/white">
 
 </com.solo.pulldown.PullDownView>

![复制代码][copycode.gif]

第二步：自定义一个listview中显示的item对象pulldown\_item.xml

![复制代码][copycode.gif]

<?xml version="1.0" encoding="utf-8"?>
 <TextView xmlns:android="http://schemas.android.com/apk/res/android"
 android:id="@android:id/text1"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:textAppearance="?android:attr/textAppearanceLarge"
 android:gravity="center_vertical"
 android:paddingLeft="6dip"
 android:minHeight="?android:attr/listPreferredItemHeight"
 android:textColor="@android:color/black"
 />

![复制代码][copycode.gif]

第三步：定义一个header的xml布局文件pulldown\_header.xml

![复制代码][copycode.gif]

<?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:paddingBottom="10dp"
 android:paddingTop="10dp" >
 
 <ImageView
 android:id="@+id/pulldown_header_arrow"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_alignParentLeft="true"
 android:layout_marginLeft="20dp"
 android:scaleType="centerCrop"
 android:src="@drawable/z_arrow_down"
 android:visibility="invisible" />
 
 <LinearLayout
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_alignBottom="@+id/pulldown_header_arrow"
 android:layout_alignTop="@+id/pulldown_header_arrow"
 android:layout_centerHorizontal="true"
 android:gravity="center_vertical"
 android:orientation="vertical" >
 
 <TextView
 android:id="@+id/pulldown_header_text"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:text="加载中..." />
 
 <TextView
 android:id="@+id/pulldown_header_date"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:text="更新于:"
 android:visibility="gone" />
 </LinearLayout>
 
 <ProgressBar
 android:id="@+id/pulldown_header_loading"
 style="@android:style/Widget.ProgressBar.Small.Inverse"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_centerVertical="true"
 android:layout_marginLeft="20dp" />
 
 </RelativeLayout>

![复制代码][copycode.gif]

第四步：如果需要向上拉更新更多的话，那就定义一个底部的footer的布局文件，在此为方便起见，只定义一个progressbar跟textview，更加复杂的显示，就交给你们了~~~~~pulldown\_footer.xml：

![复制代码][copycode.gif]

第五步：那么主要的文件这才登场：：：：：：：重写listview这个文件主要任务是提供触摸的事件的处理方法。

![复制代码][copycode.gif]

/**
 * 一个可以监听ListView是否滚动到最顶部或最底部的自定义控件
 * 只能监听由触摸产生的，如果是ListView本身Flying导致的，则不能监听
 * 如果加以改进，可以实现监听scroll滚动的具体位置等
 */
 
 public class ScrollOverListView extends ListView {
 
 private int mLastY;
 private int mTopPosition;
 private int mBottomPosition;
 
 public ScrollOverListView(Context context, AttributeSet attrs, int defStyle) {
 super(context, attrs, defStyle);
 init();
 }
 
 public ScrollOverListView(Context context, AttributeSet attrs) {
 super(context, attrs);
 init();
 }
 
 public ScrollOverListView(Context context) {
 super(context);
 init();
 }
 
 private void init(){
 mTopPosition = 0;
 mBottomPosition = 0;
 }
 
 @Override
 public boolean onTouchEvent(MotionEvent ev) {
 final int action = ev.getAction();
 final int y = (int) ev.getRawY();
 
 switch(action){
 case MotionEvent.ACTION_DOWN:{
 mLastY = y;
 final boolean isHandled = mOnScrollOverListener.onMotionDown(ev);
 if (isHandled) {
 mLastY = y;
 return isHandled;
 }
 break;
 }
 
 case MotionEvent.ACTION_MOVE:{
 final int childCount = getChildCount();
 if(childCount == 0) return super.onTouchEvent(ev);
 
 final int itemCount = getAdapter().getCount() - mBottomPosition;
 
 final int deltaY = y - mLastY;
 //DLog.d("lastY=%d y=%d", mLastY, y);
 
 final int firstTop = getChildAt(0).getTop();
 final int listPadding = getListPaddingTop();
 
 final int lastBottom = getChildAt(childCount - 1).getBottom();
 final int end = getHeight() - getPaddingBottom();
 
 final int firstVisiblePosition = getFirstVisiblePosition();
 
 final boolean isHandleMotionMove = mOnScrollOverListener.onMotionMove(ev, deltaY);
 
 if(isHandleMotionMove){
 mLastY = y;
 return true;
 }
 
 //DLog.d("firstVisiblePosition=%d firstTop=%d listPaddingTop=%d deltaY=%d", firstVisiblePosition, firstTop, listPadding, deltaY);
 if (firstVisiblePosition <= mTopPosition && firstTop >= listPadding && deltaY > 0) {
 final boolean isHandleOnListViewTopAndPullDown;
 isHandleOnListViewTopAndPullDown = mOnScrollOverListener.onListViewTopAndPullDown(deltaY);
 if(isHandleOnListViewTopAndPullDown){
 mLastY = y;
 return true;
 }
 }
 
 // DLog.d("lastBottom=%d end=%d deltaY=%d", lastBottom, end, deltaY);
 if (firstVisiblePosition + childCount >= itemCount && lastBottom <= end && deltaY < 0) {
 final boolean isHandleOnListViewBottomAndPullDown;
 isHandleOnListViewBottomAndPullDown = mOnScrollOverListener.onListViewBottomAndPullUp(deltaY);
 if(isHandleOnListViewBottomAndPullDown){
 mLastY = y;
 return true;
 }
 }
 break;
 }
 
 case MotionEvent.ACTION_UP:{
 final boolean isHandlerMotionUp = mOnScrollOverListener.onMotionUp(ev);
 if (isHandlerMotionUp) {
 mLastY = y;
 return true;
 }
 break;
 }
 }
 
 mLastY = y;
 return super.onTouchEvent(ev);
 }
 
 /**空的*/
 private OnScrollOverListener mOnScrollOverListener = new OnScrollOverListener(){
 
 @Override
 public boolean onListViewTopAndPullDown(int delta) {
 return false;
 }
 
 @Override
 public boolean onListViewBottomAndPullUp(int delta) {
 return false;
 }
 
 @Override
 public boolean onMotionDown(MotionEvent ev) {
 return false;
 }
 
 @Override
 public boolean onMotionMove(MotionEvent ev, int delta) {
 return false;
 }
 
 @Override
 public boolean onMotionUp(MotionEvent ev) {
 return false;
 }
 
 };
 
 // =============================== public method ===============================
 
 /**
 * 可以自定义其中一个条目为头部，头部触发的事件将以这个为准，默认为第一个
 *
 * @param index 正数第几个，必须在条目数范围之内
 */
 public void setTopPosition(int index){
 if(getAdapter() == null)
 throw new NullPointerException("You must set adapter before setTopPosition!");
 if(index < 0)
 throw new IllegalArgumentException("Top position must > 0");
 
 mTopPosition = index;
 }
 
 /**
 * 可以自定义其中一个条目为尾部，尾部触发的事件将以这个为准，默认为最后一个
 *
 * @param index 倒数第几个，必须在条目数范围之内
 */
 public void setBottomPosition(int index){
 if(getAdapter() == null)
 throw new NullPointerException("You must set adapter before setBottonPosition!");
 if(index < 0)
 throw new IllegalArgumentException("Bottom position must > 0");
 
 mBottomPosition = index;
 }
 
 /**
 * 设置这个Listener可以监听是否到达顶端，或者是否到达低端等事件
 *
 * @see OnScrollOverListener
 */
 public void setOnScrollOverListener(OnScrollOverListener onScrollOverListener){
 mOnScrollOverListener = onScrollOverListener;
 }
 
 /**
 * 滚动监听接口
 * @see ScrollOverListView#setOnScrollOverListener(OnScrollOverListener)
 *
 */
 public interface OnScrollOverListener {
 
 /**
 * 到达最顶部触发
 *
 * @param delta 手指点击移动产生的偏移量
 * @return
 */
 boolean onListViewTopAndPullDown(int delta);
 
 /**
 * 到达最底部触发
 *
 * @param delta 手指点击移动产生的偏移量
 * @return
 */
 boolean onListViewBottomAndPullUp(int delta);
 
 /**
 * 手指触摸按下触发，相当于{
 @link MotionEvent#ACTION_DOWN}
 *
 * @return 返回true表示自己处理
 * @see View#onTouchEvent(MotionEvent)
 */
 boolean onMotionDown(MotionEvent ev);
 
 /**
 * 手指触摸移动触发，相当于{
 @link MotionEvent#ACTION_MOVE}
 *
 * @return 返回true表示自己处理
 * @see View#onTouchEvent(MotionEvent)
 */
 boolean onMotionMove(MotionEvent ev, int delta);
 
 /**
 * 手指触摸后提起触发，相当于{
 @link MotionEvent#ACTION_UP}
 *
 * @return 返回true表示自己处理
 * @see View#onTouchEvent(MotionEvent)
 */
 boolean onMotionUp(MotionEvent ev);
 
 }
 
 }

![复制代码][copycode.gif]

第六步：下拉刷新控件，真正实现下拉刷新的是这个控件，而上面的那个ScrollOverListView只是提供触摸的事件等

![复制代码][copycode.gif]

/**
 * 下拉刷新控件
 * 真正实现下拉刷新的是这个控件，
 * ScrollOverListView只是提供触摸的事件等
 */
 public class PullDownView extends LinearLayout implements OnScrollOverListener{
 private static final String TAG = "PullDownView";
 
 private static final int START_PULL_DEVIATION = 50; // 移动误差
 private static final int AUTO_INCREMENTAL = 10; // 自增量，用于回弹
 
 private static final int WHAT_DID_LOAD_DATA = 1; // Handler what 数据加载完毕
 private static final int WHAT_ON_REFRESH = 2; // Handler what 刷新中
 private static final int WHAT_DID_REFRESH = 3; // Handler what 已经刷新完
 private static final int WHAT_SET_HEADER_HEIGHT = 4;// Handler what 设置高度
 private static final int WHAT_DID_MORE = 5; // Handler what 已经获取完更多
 
 private static final int DEFAULT_HEADER_VIEW_HEIGHT = 105; // 头部文件原本的高度
 
 private static SimpleDateFormat dateFormat = new SimpleDateFormat("MM-dd HH:mm");
 
 private View mHeaderView;
 private LayoutParams mHeaderViewParams;
 private TextView mHeaderViewDateView;
 private TextView mHeaderTextView;
 private ImageView mHeaderArrowView;
 private View mHeaderLoadingView;
 private View mFooterView;
 private TextView mFooterTextView;
 private View mFooterLoadingView;
 private ScrollOverListView mListView;
 
 private OnPullDownListener mOnPullDownListener;
 private RotateAnimation mRotateOTo180Animation;
 private RotateAnimation mRotate180To0Animation;
 
 private int mHeaderIncremental; // 增量
 private float mMotionDownLastY; // 按下时候的Y轴坐标
 
 private boolean mIsDown; // 是否按下
 private boolean mIsRefreshing; // 是否下拉刷新中
 private boolean mIsFetchMoreing; // 是否获取更多中
 private boolean mIsPullUpDone; // 是否回推完成
 private boolean mEnableAutoFetchMore; // 是否允许自动获取更多
 
 // 头部文件的状态
 private static final int HEADER_VIEW_STATE_IDLE = 0; // 空闲
 private static final int HEADER_VIEW_STATE_NOT_OVER_HEIGHT = 1; // 没有超过默认高度
 private static final int HEADER_VIEW_STATE_OVER_HEIGHT = 2; // 超过默认高度
 private int mHeaderViewState = HEADER_VIEW_STATE_IDLE;
 
 public PullDownView(Context context, AttributeSet attrs) {
 super(context, attrs);
 initHeaderViewAndFooterViewAndListView(context);
 }
 
 public PullDownView(Context context) {
 super(context);
 initHeaderViewAndFooterViewAndListView(context);
 }
 
 /*
 * ==================================
 * Public method
 * 外部使用，具体就是用这几个就可以了
 *
 * ==================================
 */
 
 /**
 * 刷新事件接口
 */
 public interface OnPullDownListener {
 void onRefresh();
 void onMore();
 }
 
 /**
 * 通知加载完了数据，要放在Adapter.notifyDataSetChanged后面
 * 当你加载完数据的时候，调用这个notifyDidLoad()
 * 才会隐藏头部，并初始化数据等
 */
 public void notifyDidLoad() {
 mUIHandler.sendEmptyMessage(WHAT_DID_LOAD_DATA);
 }
 
 /**
 * 通知已经刷新完了，要放在Adapter.notifyDataSetChanged后面
 * 当你执行完刷新任务之后，调用这个notifyDidRefresh()
 * 才会隐藏掉头部文件等操作
 */
 public void notifyDidRefresh() {
 mUIHandler.sendEmptyMessage(WHAT_DID_REFRESH);
 }
 
 /**
 * 通知已经获取完更多了，要放在Adapter.notifyDataSetChanged后面
 * 当你执行完更多任务之后，调用这个notyfyDidMore()
 * 才会隐藏加载圈等操作
 */
 public void notifyDidMore() {
 mUIHandler.sendEmptyMessage(WHAT_DID_MORE);
 }
 
 /**
 * 设置监听器
 * @param listener
 */
 public void setOnPullDownListener(OnPullDownListener listener){
 mOnPullDownListener = listener;
 }
 
 /**
 * 获取内嵌的listview
 * @return ScrollOverListView
 */
 public ListView getListView(){
 return mListView;
 }
 
 /**
 * 是否开启自动获取更多
 * 自动获取更多，将会隐藏footer，并在到达底部的时候自动刷新
 * @param index 倒数第几个触发
 */
 public void enableAutoFetchMore(boolean enable, int index){
 if(enable){
 mListView.setBottomPosition(index);
 mFooterLoadingView.setVisibility(View.VISIBLE);
 }else{
 mFooterTextView.setText("更多");
 mFooterLoadingView.setVisibility(View.GONE);
 }
 mEnableAutoFetchMore = enable;
 }
 
 /*
 * ==================================
 * Private method
 * 具体实现下拉刷新等操作
 *
 * ==================================
 */
 
 /**
 * 初始化界面
 */
 private void initHeaderViewAndFooterViewAndListView(Context context){
 setOrientation(LinearLayout.VERTICAL);
 //setDrawingCacheEnabled(false);
 /*
 * 自定义头部文件
 * 放在这里是因为考虑到很多界面都需要使用
 * 如果要修改，和它相关的设置都要更改
 */
 mHeaderView = LayoutInflater.from(context).inflate(R.layout.pulldown_header, null);
 mHeaderViewParams = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
 addView(mHeaderView, 0, mHeaderViewParams);
 
 mHeaderTextView = (TextView) mHeaderView.findViewById(R.id.pulldown_header_text);
 mHeaderArrowView = (ImageView) mHeaderView.findViewById(R.id.pulldown_header_arrow);
 mHeaderLoadingView = mHeaderView.findViewById(R.id.pulldown_header_loading);
 
 // 注意，图片旋转之后，再执行旋转，坐标会重新开始计算
 mRotateOTo180Animation = new RotateAnimation(0, 180,
 Animation.RELATIVE_TO_SELF, 0.5f,
 Animation.RELATIVE_TO_SELF, 0.5f);
 mRotateOTo180Animation.setDuration(250);
 mRotateOTo180Animation.setFillAfter(true);
 
 mRotate180To0Animation = new RotateAnimation(180, 0,
 Animation.RELATIVE_TO_SELF, 0.5f,
 Animation.RELATIVE_TO_SELF, 0.5f);
 mRotate180To0Animation.setDuration(250);
 mRotate180To0Animation.setFillAfter(true);
 
 /**
 * 自定义脚部文件
 */
 mFooterView = LayoutInflater.from(context).inflate(R.layout.pulldown_footer, null);
 mFooterTextView = (TextView) mFooterView.findViewById(R.id.pulldown_footer_text);
 mFooterLoadingView = mFooterView.findViewById(R.id.pulldown_footer_loading);
 mFooterView.setOnClickListener(new OnClickListener() {
 @Override
 public void onClick(View v) {
 if(!mIsFetchMoreing){
 mIsFetchMoreing = true;
 mFooterLoadingView.setVisibility(View.VISIBLE);
 mOnPullDownListener.onMore();
 }
 }
 });
 
 /*
 * ScrollOverListView 同样是考虑到都是使用，所以放在这里
 * 同时因为，需要它的监听事件
 */
 mListView = new ScrollOverListView(context);
 mListView.setOnScrollOverListener(this);
 mListView.setCacheColorHint(0);
 addView(mListView, LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
 
 // 空的listener
 mOnPullDownListener = new OnPullDownListener() {
 @Override
 public void onRefresh() {}
 @Override
 public void onMore() {}
 };
 }
 
 /**
 * 在下拉和回推的时候检查头部文件的状态
 * 如果超过了默认高度，就显示松开可以刷新，
 * 否则显示下拉可以刷新
 */
 private void checkHeaderViewState(){
 if(mHeaderViewParams.height >= DEFAULT_HEADER_VIEW_HEIGHT){
 if(mHeaderViewState == HEADER_VIEW_STATE_OVER_HEIGHT) return;
 mHeaderViewState = HEADER_VIEW_STATE_OVER_HEIGHT;
 mHeaderTextView.setText("松开可以刷新");
 mHeaderArrowView.startAnimation(mRotateOTo180Animation);
 }else{
 if(mHeaderViewState == HEADER_VIEW_STATE_NOT_OVER_HEIGHT
 || mHeaderViewState == HEADER_VIEW_STATE_IDLE) return;
 mHeaderViewState = HEADER_VIEW_STATE_NOT_OVER_HEIGHT;
 mHeaderTextView.setText("下拉可以刷新");
 mHeaderArrowView.startAnimation(mRotate180To0Animation);
 }
 }
 
 private void setHeaderHeight(final int height){
 mHeaderIncremental = height;
 mHeaderViewParams.height = height;
 mHeaderView.setLayoutParams(mHeaderViewParams);
 }
 
 /**
 * 自动隐藏动画
 */
 class HideHeaderViewTask extends TimerTask{
 @Override
 public void run() {
 if(mIsDown) {
 cancel();
 return;
 }
 mHeaderIncremental -= AUTO_INCREMENTAL;
 if(mHeaderIncremental > 0){
 mUIHandler.sendEmptyMessage(WHAT_SET_HEADER_HEIGHT);
 }else{
 mHeaderIncremental = 0;
 mUIHandler.sendEmptyMessage(WHAT_SET_HEADER_HEIGHT);
 cancel();
 }
 }
 }
 
 /**
 * 自动显示动画
 */
 class ShowHeaderViewTask extends TimerTask{
 
 @Override
 public void run() {
 if(mIsDown) {
 cancel();
 return;
 }
 mHeaderIncremental -= AUTO_INCREMENTAL;
 if(mHeaderIncremental > DEFAULT_HEADER_VIEW_HEIGHT){
 mUIHandler.sendEmptyMessage(WHAT_SET_HEADER_HEIGHT);
 }else{
 mHeaderIncremental = DEFAULT_HEADER_VIEW_HEIGHT;
 mUIHandler.sendEmptyMessage(WHAT_SET_HEADER_HEIGHT);
 if(!mIsRefreshing){
 mIsRefreshing = true;
 mUIHandler.sendEmptyMessage(WHAT_ON_REFRESH);
 }
 cancel();
 }
 }
 }
 
 private Handler mUIHandler = new Handler(){
 
 @Override
 public void handleMessage(Message msg) {
 switch (msg.what) {
 case WHAT_DID_LOAD_DATA:{
 mHeaderViewParams.height = 0;
 mHeaderLoadingView.setVisibility(View.GONE);
 mHeaderTextView.setText("下拉可以刷新");
 mHeaderViewDateView = (TextView) mHeaderView.findViewById(R.id.pulldown_header_date);
 mHeaderViewDateView.setVisibility(View.VISIBLE);
 mHeaderViewDateView.setText("更新于：" + dateFormat.format(new Date(System.currentTimeMillis())));
 mHeaderArrowView.setVisibility(View.VISIBLE);
 showFooterView();
 return;
 }
 
 case WHAT_ON_REFRESH:{
 // 要清除掉动画，否则无法隐藏
 mHeaderArrowView.clearAnimation();
 mHeaderArrowView.setVisibility(View.INVISIBLE);
 mHeaderLoadingView.setVisibility(View.VISIBLE);
 mOnPullDownListener.onRefresh();
 return;
 }
 
 case WHAT_DID_REFRESH :{
 mIsRefreshing = false;
 mHeaderViewState = HEADER_VIEW_STATE_IDLE;
 mHeaderArrowView.setVisibility(View.VISIBLE);
 mHeaderLoadingView.setVisibility(View.GONE);
 mHeaderViewDateView.setText("更新于：" + dateFormat.format(new Date(System.currentTimeMillis())));
 setHeaderHeight(0);
 showFooterView();
 return;
 }
 
 case WHAT_SET_HEADER_HEIGHT :{
 setHeaderHeight(mHeaderIncremental);
 return;
 }
 
 case WHAT_DID_MORE :{
 mIsFetchMoreing = false;
 mFooterTextView.setText("更多");
 mFooterLoadingView.setVisibility(View.GONE);
 }
 }
 }
 
 };
 
 /**
 * 显示脚步脚部文件
 */
 private void showFooterView(){
 if(mListView.getFooterViewsCount() == 0 && isFillScreenItem()){
 mListView.addFooterView(mFooterView);
 mListView.setAdapter(mListView.getAdapter());
 }
 }
 
 /**
 * 条目是否填满整个屏幕
 */
 private boolean isFillScreenItem(){
 final int firstVisiblePosition = mListView.getFirstVisiblePosition();
 final int lastVisiblePostion = mListView.getLastVisiblePosition() - mListView.getFooterViewsCount();
 final int visibleItemCount = lastVisiblePostion - firstVisiblePosition + 1;
 final int totalItemCount = mListView.getCount() - mListView.getFooterViewsCount();
 
 if(visibleItemCount < totalItemCount) return true;
 return false;
 }
 
 /*
 * ==================================
 * 实现 OnScrollOverListener接口
 *
 *
 * ==================================
 */
 
 @Override
 public boolean onListViewTopAndPullDown(int delta) {
 if(mIsRefreshing || mListView.getCount() - mListView.getFooterViewsCount() == 0) return false;
 
 int absDelta = Math.abs(delta);
 final int i = (int) Math.ceil((double)absDelta / 2);
 
 mHeaderIncremental += i;
 if(mHeaderIncremental >= 0){ // && mIncremental <= mMaxHeight
 setHeaderHeight(mHeaderIncremental);
 checkHeaderViewState();
 }
 return true;
 }
 
 @Override
 public boolean onListViewBottomAndPullUp(int delta) {
 if(!mEnableAutoFetchMore || mIsFetchMoreing) return false;
 // 数量充满屏幕才触发
 if(isFillScreenItem()){
 mIsFetchMoreing = true;
 mFooterTextView.setText("加载更多中...");
 mFooterLoadingView.setVisibility(View.VISIBLE);
 mOnPullDownListener.onMore();
 return true;
 }
 return false;
 }
 
 @Override
 public boolean onMotionDown(MotionEvent ev) {
 mIsDown = true;
 mIsPullUpDone = false;
 mMotionDownLastY = ev.getRawY();
 return false;
 }
 
 @Override
 public boolean onMotionMove(MotionEvent ev, int delta) {
 //当头部文件回推消失的时候，不允许滚动
 if(mIsPullUpDone) return true;
 
 // 如果开始按下到滑动距离不超过误差值，则不滑动
 final int absMotionY = (int) Math.abs(ev.getRawY() - mMotionDownLastY);
 if(absMotionY < START_PULL_DEVIATION) return true;
 
 final int absDelta = Math.abs(delta);
 final int i = (int) Math.ceil((double)absDelta / 2);
 
 // onTopDown在顶部，并上回推和onTopUp相对
 if(mHeaderViewParams.height > 0 && delta < 0){
 mHeaderIncremental -= i;
 if(mHeaderIncremental > 0){
 setHeaderHeight(mHeaderIncremental);
 checkHeaderViewState();
 }else{
 mHeaderViewState = HEADER_VIEW_STATE_IDLE;
 mHeaderIncremental = 0;
 setHeaderHeight(mHeaderIncremental);
 mIsPullUpDone = true;
 }
 return true;
 }
 return false;
 }
 
 @Override
 public boolean onMotionUp(MotionEvent ev) {
 mIsDown = false;
 // 避免和点击事件冲突
 if(mHeaderViewParams.height > 0){
 // 判断头文件拉动的距离与设定的高度，小了就隐藏，多了就固定高度
 int x = mHeaderIncremental - DEFAULT_HEADER_VIEW_HEIGHT;
 Timer timer = new Timer(true);
 if(x < 0){
 timer.scheduleAtFixedRate(new HideHeaderViewTask(), 0, 10);
 }else{
 timer.scheduleAtFixedRate(new ShowHeaderViewTask(), 0, 10);
 }
 return true;
 }
 return false;
 }
 
 }

![复制代码][copycode.gif]

第七步：这个java文件就是封装数据，然后调用上两个文件就好了。废话不多说，上代码：：：：：

![复制代码][copycode.gif]

public class PullDownActivity extends Activity implements OnPullDownListener, OnItemClickListener{
 
 private static final int WHAT_DID_LOAD_DATA = 0;
 private static final int WHAT_DID_REFRESH = 1;
 private static final int WHAT_DID_MORE = 2;
 
 private ListView mListView;
 private ArrayAdapter<String> mAdapter;
 
 private PullDownView mPullDownView;
 private List<String> mStrings = new ArrayList<String>();
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.pulldown);
 
 /*
 * 1.使用PullDownView
 * 2.设置OnPullDownListener
 * 3.从mPullDownView里面获取ListView
 */
 mPullDownView = (PullDownView) findViewById(R.id.pull_down_view);
 mPullDownView.setOnPullDownListener(this);
 mListView = mPullDownView.getListView();
 
 mListView.setOnItemClickListener(this);
 mAdapter = new ArrayAdapter<String>(this, R.layout.pulldown_item, mStrings);
 mListView.setAdapter(mAdapter);
 
 mPullDownView.enableAutoFetchMore(true, 1);
 
 loadData();
 }
 
 private void loadData(){
 new Thread(new Runnable() {
 
 @Override
 public void run() {
 try {
 Thread.sleep(2000);
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 List<String> strings = new ArrayList<String>();
 for (String body : mStringArray) {
 strings.add(body);
 }
 Message msg = mUIHandler.obtainMessage(WHAT_DID_LOAD_DATA);
 msg.obj = strings;
 msg.sendToTarget();
 }
 }).start();
 }
 
 @Override
 public void onRefresh() {
 new Thread(new Runnable() {
 
 @Override
 public void run() {
 try {
 Thread.sleep(2000);
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 Message msg = mUIHandler.obtainMessage(WHAT_DID_REFRESH);
 msg.obj = "After refresh " + System.currentTimeMillis();
 msg.sendToTarget();
 }
 }).start();
 }
 
 @Override
 public void onMore() {
 new Thread(new Runnable() {
 
 @Override
 public void run() {
 try {
 Thread.sleep(2000);
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 Message msg = mUIHandler.obtainMessage(WHAT_DID_MORE);
 msg.obj = "After more " + System.currentTimeMillis();
 msg.sendToTarget();
 }
 }).start();
 }
 
 private Handler mUIHandler = new Handler(){
 
 @Override
 public void handleMessage(Message msg) {
 switch (msg.what) {
 case WHAT_DID_LOAD_DATA:{
 if(msg.obj != null){
 List<String> strings = (List<String>) msg.obj;
 if(!strings.isEmpty()){
 mStrings.addAll(strings);
 mAdapter.notifyDataSetChanged();
 }
 }
 // 诉它数据加载完毕;
 mPullDownView.notifyDidLoad();
 break;
 }
 case WHAT_DID_REFRESH :{
 String body = (String) msg.obj;
 mStrings.add(0, body);
 mAdapter.notifyDataSetChanged();
 // 告诉它更新完毕
 mPullDownView.notifyDidRefresh();
 break;
 }
 
 case WHAT_DID_MORE:{
 String body = (String) msg.obj;
 mStrings.add(body);
 mAdapter.notifyDataSetChanged();
 // 告诉它获取更多完毕
 mPullDownView.notifyDidMore();
 break;
 }
 }
 
 }
 
 };
 
 @Override
 public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
 Toast.makeText(this, "啊，你点中我了 " + position, Toast.LENGTH_SHORT).show();
 }
 
 // 模拟数据
 private String[] mStringArray = {
 "Abbaye de Belloc", "Abbaye du Mont des Cats", "Abertam", "Abondance", "Ackawi",
 "Acorn", "Adelost", "Affidelice au Chablis", "Afuega'l Pitu", "Airag", "Airedale",
 "Aisy Cendre", "Allgauer Emmentaler", "Alverca", "Ambert", "American Cheese"
 };
 
 }

![复制代码][copycode.gif]

整个程序就这么完成了，总之，可以使用前两个封装好的文件，然后，调用就好了~~~~没什么太难的地方。

![25162623-e5fcbbdc8fe34941b7edf29df8a279e6.jpg][]

![25162654-f4358156ceda4ff995dec26f8a72afa3.jpg][]

源代码下载地址：[我是传送门][Link 1]   [我也是个传送门][Link 2]

[http://k-beta.com/android-listview-more-refresh.html][http_k-beta.com_android-listview-more-refresh.html]

[25162259-5fa5cedfdc6d4b8bb1134393218f3534.jpg]: /images/20220731/7a42437f4fae47f79fae3a6e3f55e8f6.png
[25162321-14aaa3e697e64d1dadf5cc4ed5d3edcf.jpg]: /images/20220731/8df6683f284b4569881b8655a3195665.png
[25162338-601950593f10400d9dd761e044a24b74.jpg]: /images/20220731/cce29ca0892243ad9796d0feb2eae20e.png
[copycode.gif]: /images/20220731/533e332b2a304fa09e8877b7193ffc80.png
[25162623-e5fcbbdc8fe34941b7edf29df8a279e6.jpg]: /images/20220731/7979d2ab147f4037900d7d694a4a17e6.png
[25162654-f4358156ceda4ff995dec26f8a72afa3.jpg]: /images/20220731/171b311c5ad341b98788bbb1f8744aae.png
[Link 1]: http://115.com/file/c2cp4eqk#PullDownDemo.rar
[Link 2]: http://dl.dbank.com/c0m5fr21qi
[http_k-beta.com_android-listview-more-refresh.html]: http://k-beta.com/android-listview-more-refresh.html