自定义布局实现listview上拉加载下拉刷新

listview布局有时加载数据偏多，需要上拉加载第二页等更多数据，下拉刷新数据等功能，也有开源的框架XRefreshView ，可以参考http://www.w2bc.com/Article/44291，当初开发项目时，便于自己控制，就自定义布局实现这功能。

1、自定义布局用来管理三个子控件：下拉头，包含内容的自定义listview，上拉头（代码有详细介绍）

public class PullToRefreshLayout extends RelativeLayout {
public static final String TAG = "PullToRefreshLayout";
// 初始状态
public static final int INIT = 0;
// 释放刷新
public static final int RELEASE_TO_REFRESH = 1;
// 正在刷新
public static final int REFRESHING = 2;
// 释放加载
public static final int RELEASE_TO_LOAD = 3;
// 正在加载
public static final int LOADING = 4;
// 操作完毕
public static final int DONE = 5;
// 当前状态
private int state = INIT;
// 刷新回调接口
private OnRefreshListener mListener;
// 刷新成功
public static final int SUCCEED = 0;
// 刷新失败
public static final int FAIL = 1;
// 按下Y坐标，上一个事件点Y坐标
private float downY, lastY;

// 下拉的距离。注意：pullDownY和pullUpY不可能同时不为0
public float pullDownY = 0;
// 上拉的距离
private float pullUpY = 0;

// 释放刷新的距离
private float refreshDist = 200;
// 释放加载的距离
private float loadmoreDist = 200;

private MyTimer timer;
// 回滚速度
public float MOVE_SPEED = 8;
// 第一次执行布局
private boolean isLayout = false;
// 在刷新过程中滑动操作
private boolean isTouch = false;
// 手指滑动距离与下拉头的滑动距离比，中间会随正切函数变化
private float radio = 2;

// 下拉箭头的转180°动画
private RotateAnimation rotateAnimation;
// 均匀旋转动画
private RotateAnimation refreshingAnimation;

// 下拉头
private View refreshView;
// 下拉的箭头
private View pullView;
// 正在刷新的图标
private View refreshingView;
// 刷新结果图标
private View refreshStateImageView;
// 刷新结果：成功或失败
private TextView refreshStateTextView;

// 上拉头
private View loadmoreView;
// 上拉的箭头
private View pullUpView;
// 正在加载的图标
private View loadingView;
// 加载结果图标
private View loadStateImageView;
// 加载结果：成功或失败
private TextView loadStateTextView;

// 实现了Pullable接口的View
private View pullableView;
// 过滤多点触碰
private int mEvents;
// 这两个变量用来控制pull的方向，如果不加控制，当情况满足可上拉又可下拉时没法下拉
private boolean canPullDown = true;
private boolean canPullUp = true;

/**
* 执行自动回滚的handler
*/
Handler updateHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
// 回弹速度随下拉距离moveDeltaY增大而增大
MOVE_SPEED = (float) (8 + 5 * Math.tan(Math.PI / 2
/ getMeasuredHeight() * (pullDownY + Math.abs(pullUpY))));
if (!isTouch) {
// 正在刷新，且没有往上推的话则悬停，显示"正在刷新..."
if (state == REFRESHING && pullDownY <= refreshDist) {
pullDownY = refreshDist;
timer.cancel();
} else if (state == LOADING && -pullUpY <= loadmoreDist) {
pullUpY = -loadmoreDist;
timer.cancel();
}

}
if (pullDownY > 0)
pullDownY -= MOVE_SPEED;
else if (pullUpY < 0)
pullUpY += MOVE_SPEED;
if (pullDownY < 0) {
// 已完成回弹
pullDownY = 0;
pullView.clearAnimation();
// 隐藏下拉头时有可能还在刷新，只有当前状态不是正在刷新时才改变状态
if (state != REFRESHING && state != LOADING)
changeState(INIT);
timer.cancel();
}
if (pullUpY > 0) {
// 已完成回弹
pullUpY = 0;
pullUpView.clearAnimation();
// 隐藏下拉头时有可能还在刷新，只有当前状态不是正在刷新时才改变状态
if (state != REFRESHING && state != LOADING)
changeState(INIT);
timer.cancel();
}
// 刷新布局,会自动调用onLayout
requestLayout();
}

};

public void setOnRefreshListener(OnRefreshListener listener) {
mListener = listener;
}

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

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

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

private void initView(Context context) {
timer = new MyTimer(updateHandler);
rotateAnimation = (RotateAnimation) AnimationUtils.loadAnimation(
context, R.anim.reverse_anim);
refreshingAnimation = (RotateAnimation) AnimationUtils.loadAnimation(
context, R.anim.rotating);
// 添加匀速转动动画
LinearInterpolator lir = new LinearInterpolator();
rotateAnimation.setInterpolator(lir);
refreshingAnimation.setInterpolator(lir);
}

private void hide() {
timer.schedule(5);
}

/**
* 完成刷新操作，显示刷新结果(注意：刷新完成后一定要调用这个方法)
*
* @param refreshResult  PullToRefreshLayout.SUCCEED代表成功，PullToRefreshLayout.FAIL代表失败
* void
*
*/
public void refreshFinish(int refreshResult) {
refreshingView.clearAnimation();
refreshingView.setVisibility(View.GONE);
switch (refreshResult) {
case SUCCEED:
// 刷新成功
refreshStateImageView.setVisibility(View.VISIBLE);
refreshStateTextView.setText(R.string.refresh_succeed);
refreshStateImageView.setBackgroundResource(R.drawable.refresh_succeed);
break;
case FAIL:
default:
// 刷新失败
refreshStateImageView.setVisibility(View.VISIBLE);
refreshStateTextView.setText(R.string.refresh_fail);
refreshStateImageView.setBackgroundResource(R.drawable.refresh_failed);
break;
}
// 刷新结果停留1秒
new Handler() {
@Override
public void handleMessage(Message msg) {
changeState(DONE);
hide();
}
}.sendEmptyMessageDelayed(0, 1000);
}

/**
* 加载完毕，显示加载结果(注意：加载完成后一定要调用这个方法)
*
* @param refreshResult  PullToRefreshLayout.SUCCEED代表成功，PullToRefreshLayout.FAIL代表失败
* void
*
*/
public void loadmoreFinish(int refreshResult) {
loadingView.clearAnimation();
loadingView.setVisibility(View.GONE);
switch (refreshResult) {
case SUCCEED:
// 加载成功
loadStateImageView.setVisibility(View.VISIBLE);
loadStateTextView.setText(R.string.load_succeed);
loadStateImageView.setBackgroundResource(R.drawable.load_succeed);
break;
case FAIL:
default:
// 加载失败
loadStateImageView.setVisibility(View.VISIBLE);
loadStateTextView.setText(R.string.load_fail);
loadStateImageView.setBackgroundResource(R.drawable.load_failed);
break;
}
// 刷新结果停留1秒
new Handler() {
@Override
public void handleMessage(Message msg) {
changeState(DONE);
hide();
}
}.sendEmptyMessageDelayed(0, 1000);
}

private void changeState(int to) {
state = to;
switch (state) {
case INIT:
// 下拉布局初始状态
refreshStateImageView.setVisibility(View.GONE);
refreshStateTextView.setText(R.string.pull_to_refresh);
pullView.clearAnimation();
pullView.setVisibility(View.VISIBLE);
// 上拉布局初始状态
loadStateImageView.setVisibility(View.GONE);
loadStateTextView.setText(R.string.pullup_to_load);
pullUpView.clearAnimation();
pullUpView.setVisibility(View.VISIBLE);
break;
case RELEASE_TO_REFRESH:
// 释放刷新状态
refreshStateTextView.setText(R.string.release_to_refresh);
pullView.startAnimation(rotateAnimation);
break;
case REFRESHING:
// 正在刷新状态
pullView.clearAnimation();
refreshingView.setVisibility(View.VISIBLE);
pullView.setVisibility(View.INVISIBLE);
refreshingView.startAnimation(refreshingAnimation);
refreshStateTextView.setText(R.string.refreshing);
break;
case RELEASE_TO_LOAD:
// 释放加载状态
loadStateTextView.setText(R.string.release_to_load);
pullUpView.startAnimation(rotateAnimation);
break;
case LOADING:
// 正在加载状态
pullUpView.clearAnimation();
loadingView.setVisibility(View.VISIBLE);
pullUpView.setVisibility(View.INVISIBLE);
loadingView.startAnimation(refreshingAnimation);
loadStateTextView.setText(R.string.loading);
break;
case DONE:
// 刷新或加载完毕，啥都不做
break;
}
}

/**
* 不限制上拉或下拉
*/
private void releasePull() {
canPullDown = true;
canPullUp = true;
}

@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
switch (ev.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
downY = ev.getY();
lastY = downY;
timer.cancel();
mEvents = 0;
releasePull();
break;
case MotionEvent.ACTION_POINTER_DOWN:
case MotionEvent.ACTION_POINTER_UP:
// 过滤多点触碰
mEvents = -1;
break;
case MotionEvent.ACTION_MOVE:
if (mEvents == 0) {
if (((Pullable) pullableView).canPullDown() && canPullDown
&& state != LOADING) {
// 可以下拉，正在加载时不能下拉
// 对实际滑动距离做缩小，造成用力拉的感觉
pullDownY = pullDownY + (ev.getY() - lastY) / radio;
if (pullDownY < 0) {
pullDownY = 0;
canPullDown = false;
canPullUp = true;
}
if (pullDownY > getMeasuredHeight())
pullDownY = getMeasuredHeight();
if (state == REFRESHING) {
// 正在刷新的时候触摸移动
isTouch = true;
}
} else if (((Pullable) pullableView).canPullUp() && canPullUp
&& state != REFRESHING) {
// 可以上拉，正在刷新时不能上拉
pullUpY = pullUpY + (ev.getY() - lastY) / radio;
if (pullUpY > 0) {
pullUpY = 0;
canPullDown = true;
canPullUp = false;
}
if (pullUpY < -getMeasuredHeight())
pullUpY = -getMeasuredHeight();
if (state == LOADING) {
// 正在加载的时候触摸移动
isTouch = true;
}
} else
releasePull();
} else
mEvents = 0;
lastY = ev.getY();
// 根据下拉距离改变比例
radio = (float) (2 + 2 * Math.tan(Math.PI / 2 / getMeasuredHeight()
* (pullDownY + Math.abs(pullUpY))));
requestLayout();
if (pullDownY <= refreshDist && state == RELEASE_TO_REFRESH) {
// 如果下拉距离没达到刷新的距离且当前状态是释放刷新，改变状态为下拉刷新
changeState(INIT);
}
if (pullDownY >= refreshDist && state == INIT) {
// 如果下拉距离达到刷新的距离且当前状态是初始状态刷新，改变状态为释放刷新
changeState(RELEASE_TO_REFRESH);
}
// 下面是判断上拉加载的，同上，注意pullUpY是负值
if (-pullUpY <= loadmoreDist && state == RELEASE_TO_LOAD) {
changeState(INIT);
}
if (-pullUpY >= loadmoreDist && state == INIT) {
changeState(RELEASE_TO_LOAD);
}
// 因为刷新和加载操作不能同时进行，所以pullDownY和pullUpY不会同时不为0，因此这里用(pullDownY +
// Math.abs(pullUpY))就可以不对当前状态作区分了
if ((pullDownY + Math.abs(pullUpY)) > 8) {
// 防止下拉过程中误触发长按事件和点击事件
ev.setAction(MotionEvent.ACTION_CANCEL);
}
break;
case MotionEvent.ACTION_UP:
if (pullDownY > refreshDist || -pullUpY > loadmoreDist)
// 正在刷新时往下拉（正在加载时往上拉），释放后下拉头（上拉头）不隐藏
isTouch = false;
if (state == RELEASE_TO_REFRESH) {
changeState(REFRESHING);
// 刷新操作
if (mListener != null)
mListener.onRefresh(this);
} else if (state == RELEASE_TO_LOAD) {
changeState(LOADING);
// 加载操作
if (mListener != null)
mListener.onLoadMore(this);
}
hide();
default:
break;
}
// 事件分发交给父类
super.dispatchTouchEvent(ev);
return true;
}

private void initView() {
// 初始化下拉布局
pullView = refreshView.findViewById(R.id.pull_icon);
refreshStateTextView = (TextView) refreshView.findViewById(R.id.state_tv);
refreshingView = refreshView.findViewById(R.id.refreshing_icon);
refreshStateImageView = refreshView.findViewById(R.id.state_iv);
// 初始化上拉布局
pullUpView = loadmoreView.findViewById(R.id.pullup_icon);
loadStateTextView = (TextView) loadmoreView.findViewById(R.id.loadstate_tv);
loadingView = loadmoreView.findViewById(R.id.loading_icon);
loadStateImageView = loadmoreView.findViewById(R.id.loadstate_iv);
}

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (!isLayout) {
// 这里是第一次进来的时候做一些初始化
refreshView = getChildAt(0);
pullableView = getChildAt(1);
loadmoreView = getChildAt(2);
isLayout = true;
initView();
refreshDist = ((ViewGroup) refreshView).getChildAt(0).getMeasuredHeight();
loadmoreDist = ((ViewGroup) loadmoreView).getChildAt(0).getMeasuredHeight();
}
// 改变子控件的布局，这里直接用(pullDownY + pullUpY)作为偏移量，这样就可以不对当前状态作区分
refreshView.layout(0,
(int) (pullDownY + pullUpY) - refreshView.getMeasuredHeight(),
refreshView.getMeasuredWidth(), (int) (pullDownY + pullUpY));
pullableView.layout(0, (int) (pullDownY + pullUpY),
pullableView.getMeasuredWidth(), (int) (pullDownY + pullUpY)
+ pullableView.getMeasuredHeight());
loadmoreView.layout(0,
(int) (pullDownY + pullUpY) + pullableView.getMeasuredHeight(),
loadmoreView.getMeasuredWidth(),
(int) (pullDownY + pullUpY) + pullableView.getMeasuredHeight()
+ loadmoreView.getMeasuredHeight());
}

class MyTimer {
private Handler handler;
private Timer timer;
private MyTask mTask;

public MyTimer(Handler handler) {
this.handler = handler;
timer = new Timer();
}

public void schedule(long period) {
if (mTask != null) {
mTask.cancel();
mTask = null;
}
mTask = new MyTask(handler);
timer.schedule(mTask, 0, period);
}

public void cancel() {
if (mTask != null) {
mTask.cancel();
mTask = null;
}
}

class MyTask extends TimerTask {
private Handler handler;

public MyTask(Handler handler) {
this.handler = handler;
}

@Override
public void run() {
handler.obtainMessage().sendToTarget();
}

}
}

/**
* 刷新加载回调接口
*/
public interface OnRefreshListener {
/**
* 刷新操作
*/
void onRefresh(PullToRefreshLayout pullToRefreshLayout);

/**
* 加载操作
*/
void onLoadMore(PullToRefreshLayout pullToRefreshLayout);
}

}

2、定义上拉下拉的事件的接口

public interface Pullable {

/**
* 判断是否可以下拉，如果不需要下拉功能可以直接return false
*
* @创建日期 2015年10月19日
*
* @return boolean true如果可以下拉否则返回false
*/
boolean canPullDown();

/**
* 判断是否可以上拉，如果不需要上拉功能可以直接return false
*
* @创建日期 2015年10月19日
*
* @return boolean  true如果可以上拉否则返回false
*
*/
boolean canPullUp();
}

3、自定义listview实现上拉下拉的事件操作

public class PullableListView extends ListView implements Pullable {

public PullableListView(Context context) {
super(context);
}

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

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

@Override
public boolean canPullDown() {
if (getCount() == 0) { // 没有item的时候也可以下拉刷新
return true;
} else if (getFirstVisiblePosition() == 0
&& getChildAt(0).getTop() >= 0) {
// 滑到ListView的顶部
return true;
} else{
return false;
}
}

@Override
public boolean canPullUp() {
if (getCount() == 0) { // 没有item的时候也可以上拉加载
return true;
} else if (getLastVisiblePosition() == (getCount() - 1)) { // 滑到底部了
if (getChildAt(getLastVisiblePosition() - getFirstVisiblePosition()) != null
&& getChildAt(getLastVisiblePosition()- getFirstVisiblePosition()).getBottom() <= getMeasuredHeight())
return true;
}
return false;
}
}

4、布局

<cn.com.supplier.view.PullToRefreshLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/project_refresh_view"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<!-- 下拉刷新布局 -->
<include layout="@layout/refresh_head" />

<!-- 支持所有实现Pullable接口的View -->
<cn.com.supplier.view.PullableListView
android:id="@+id/list_enrollProject"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/bg"
android:divider="@color/list_line"
android:dividerHeight="1dp" />

<!-- 上拉加载布局 -->
<include layout="@layout/load_more" />

</cn.com.supplier.view.PullToRefreshLayout>

其中上拉和下拉的布局是分开引入的，自己可以根据样式自定义

5、调用

先获取自定义布局,实现自定义的刷新方法

((PullToRefreshLayout) findViewById(R.id.project_refresh_view)).setOnRefreshListener(new MyClickListener());

class MyClickListener implements OnRefreshListener {
/**
* 下拉刷新操作
*/
@Override
public void onRefresh(final PullToRefreshLayout pullToRefreshLayout) {

new Handler() {
@Override
public void handleMessage(Message msg) {
pullToRefreshLayout.refreshFinish(PullToRefreshLayout.SUCCEED);
onDestroy();
}
}.sendEmptyMessageDelayed(0, 1000);
}

/**
* 上拉加载更多操作
*/
@Override
public void onLoadMore(final PullToRefreshLayout pullToRefreshLayout) {
new Handler() {
@Override
public void handleMessage(Message msg) {

//获取更多数据的方法
loadProjectPost(signUrl);
pullToRefreshLayout.loadmoreFinish(PullToRefreshLayout.SUCCEED);
}
}.sendEmptyMessageDelayed(0, 1000);
}

}