Android下拉刷新上拉加载控件，对所有View通用！

转载请声明出处http://blog.csdn.net/zhongkejingwang/article/details/38868463

前面写过一篇关于下拉刷新控件的博客下拉刷新控件终结者：PullToRefreshLayout，后来看到好多人还有上拉加载更多的需求，于是就在前面下拉刷新控件的基础上进行了改进，加了上拉加载的功能。不仅如此，我已经把它改成了对所有View都通用！可以随心所欲使用这两个功能~~

我做了一个大集合的demo，实现了ListView、GridView、ExpandableListView、ScrollView、WebView、ImageView、TextView的下拉刷新和上拉加载。后面会提供demo的下载地址。（csdn上的demo有小bug，最新代码已上传到github：https://github.com/jingchenUSTC/PullToRefreshAndLoad)

依照惯例，下面将会是一大波效果图：

demo首页也是可下拉的ListView，在底下可以加入table：

ListView：

GridView：

ExpandableListView：

ScrollView：

WebView：

ImageView：

TextView：

很不错吧？最后的ImageView和TextView是最简单的，直接在下面的接口方法里返回true。

增加上拉加载很简单，和管理下拉头一样，再多管理一个上拉头，也不费事；至于把它改成通用的就需要统一一下View的行为了，为此，我定义了这样一个接口：

**[java]** [view plain](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)[copy](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)

  <div>
    <embed id="ZeroClipboardMovie_1" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_1">
    </embed>
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- <span class="keyword">package</span> com.jingchen.pulltorefresh.pullableview;

- 
- <span class="keyword">public</span> <span class="keyword">interface</span> Pullable

- {

- <span class="comment">/**</span>

- <span class="comment">     * 判断是否可以下拉，如果不需要下拉功能可以直接return false</span>

- <span class="comment">     * </span>

- <span class="comment">     * @return true如果可以下拉否则返回false</span>

- <span class="comment">     */</span>

- <span class="keyword">boolean</span> canPullDown();

- 
- <span class="comment">/**</span>

- <span class="comment">     * 判断是否可以上拉，如果不需要上拉功能可以直接return false</span>

- <span class="comment">     * </span>

- <span class="comment">     * @return true如果可以上拉否则返回false</span>

- <span class="comment">     */</span>

- <span class="keyword">boolean</span> canPullUp();

- }

从接口名就可以看出它是一个提供判断是否可拉的方法的接口。这个接口的两个方法，canPullDown()是判断何时可以下拉的方法，canPullUp()则是判断何时可以上拉，我在demo中的判断是滑到顶部的时候可以下拉，滑到底部的时候可以上拉。所有需要上拉和下拉的 View都需要实现这个接口。后面会给出一些View的实现。先来看看改进后的自定义的布局PullToRefreshLayout，增加了一个上拉头，下拉头和上拉头之间的View是实现了Pullable接口的pullableView。相比前面的版本，这里有改动的需要注意的地方如下：

1、增加了上拉头，相应的也增加了控制变量。

2、拉动时消除content_view事件防止误触发不再使用反射，直接设置 event.setAction(MotionEvent.ACTION_CANCEL)。

3、消除了拉动过程中的多点触碰导致的剧变。

4、不再设置content_view的onTouListener，让使用者可以更加自由的设置监听器。

这个PullToRefreshLayout只负责管理三个控件，如果一个View需要有上拉下拉功能则只需实现接口就行了。下面看PullToRefreshLayout的代码，注释写了好多：

**[java]** [view plain](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)[copy](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)

  <div>
    <embed id="ZeroClipboardMovie_2" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_2">
    </embed>
  </div>
</div>

- <span class="keyword">package</span> com.jingchen.pulltorefresh;

- 
- <span class="keyword">import</span> java.util.Timer;

- <span class="keyword">import</span> java.util.TimerTask;

- 
- <span class="keyword">import</span> android.content.Context;

- <span class="keyword">import</span> android.graphics.Canvas;

- <span class="keyword">import</span> android.graphics.LinearGradient;

- <span class="keyword">import</span> android.graphics.Paint;

- <span class="keyword">import</span> android.graphics.Paint.Style;

- <span class="keyword">import</span> android.graphics.RectF;

- <span class="keyword">import</span> android.graphics.Shader.TileMode;

- <span class="keyword">import</span> android.os.Handler;

- <span class="keyword">import</span> android.os.Message;

- <span class="keyword">import</span> android.util.AttributeSet;

- <span class="keyword">import</span> android.util.Log;

- <span class="keyword">import</span> android.view.MotionEvent;

- <span class="keyword">import</span> android.view.View;

- <span class="keyword">import</span> android.view.ViewGroup;

- <span class="keyword">import</span> android.view.animation.AnimationUtils;

- <span class="keyword">import</span> android.view.animation.LinearInterpolator;

- <span class="keyword">import</span> android.view.animation.RotateAnimation;

- <span class="keyword">import</span> android.widget.RelativeLayout;

- <span class="keyword">import</span> android.widget.TextView;

- 
- <span class="keyword">import</span> com.jingchen.pulltorefresh.pullableview.Pullable;

- 
- <span class="comment">/**</span>

- <span class="comment"> * 自定义的布局，用来管理三个子控件，其中一个是下拉头，一个是包含内容的pullableView（可以是实现Pullable接口的的任何View），</span>

- <span class="comment"> * 还有一个上拉头</span>

- <span class="comment"> * </span>

- <span class="comment"> * @author 陈靖</span>

- <span class="comment"> */</span>

- <span class="keyword">public</span> <span class="keyword">class</span> PullToRefreshLayout <span class="keyword">extends</span> RelativeLayout

- {

- <span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">final</span> String TAG = <span class="string">&#8220;PullToRefreshLayout&#8221;</span>;

- <span class="comment">// 初始状态</span>

- <span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">final</span> <span class="keyword">int</span> INIT = <span class="number"></span>;

- <span class="comment">// 释放刷新</span>

- <span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">final</span> <span class="keyword">int</span> RELEASE_TO_REFRESH = <span class="number">1</span>;

- <span class="comment">// 正在刷新</span>

- <span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">final</span> <span class="keyword">int</span> REFRESHING = <span class="number">2</span>;

- <span class="comment">// 释放加载</span>

- <span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">final</span> <span class="keyword">int</span> RELEASE_TO_LOAD = <span class="number">3</span>;

- <span class="comment">// 正在加载</span>

- <span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">final</span> <span class="keyword">int</span> LOADING = <span class="number">4</span>;

- <span class="comment">// 操作完毕</span>

- <span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">final</span> <span class="keyword">int</span> DONE = <span class="number">5</span>;

- <span class="comment">// 当前状态</span>

- <span class="keyword">private</span> <span class="keyword">int</span> state = INIT;

- <span class="comment">// 刷新回调接口</span>

- <span class="keyword">private</span> OnRefreshListener mListener;

- <span class="comment">// 刷新成功</span>

- <span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">final</span> <span class="keyword">int</span> SUCCEED = <span class="number"></span>;

- <span class="comment">// 刷新失败</span>

- <span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">final</span> <span class="keyword">int</span> FAIL = <span class="number">1</span>;

- <span class="comment">// 按下Y坐标，上一个事件点Y坐标</span>

- <span class="keyword">private</span> <span class="keyword">float</span> downY, lastY;

- 
- <span class="comment">// 下拉的距离。注意：pullDownY和pullUpY不可能同时不为0</span>

- <span class="keyword">public</span> <span class="keyword">float</span> pullDownY = <span class="number"></span>;

- <span class="comment">// 上拉的距离</span>

- <span class="keyword">private</span> <span class="keyword">float</span> pullUpY = <span class="number"></span>;

- 
- <span class="comment">// 释放刷新的距离</span>

- <span class="keyword">private</span> <span class="keyword">float</span> refreshDist = <span class="number">200</span>;

- <span class="comment">// 释放加载的距离</span>

- <span class="keyword">private</span> <span class="keyword">float</span> loadmoreDist = <span class="number">200</span>;

- 
- <span class="keyword">private</span> MyTimer timer;

- <span class="comment">// 回滚速度</span>

- <span class="keyword">public</span> <span class="keyword">float</span> MOVE_SPEED = <span class="number">8</span>;

- <span class="comment">// 第一次执行布局</span>

- <span class="keyword">private</span> <span class="keyword">boolean</span> isLayout = <span class="keyword">false</span>;

- <span class="comment">// 在刷新过程中滑动操作</span>

- <span class="keyword">private</span> <span class="keyword">boolean</span> isTouch = <span class="keyword">false</span>;

- <span class="comment">// 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</span>

- <span class="keyword">private</span> <span class="keyword">float</span> radio = <span class="number">2</span>;

- 
- <span class="comment">// 下拉箭头的转180°动画</span>

- <span class="keyword">private</span> RotateAnimation rotateAnimation;

- <span class="comment">// 均匀旋转动画</span>

- <span class="keyword">private</span> RotateAnimation refreshingAnimation;

- 
- <span class="comment">// 下拉头</span>

- <span class="keyword">private</span> View refreshView;

- <span class="comment">// 下拉的箭头</span>

- <span class="keyword">private</span> View pullView;

- <span class="comment">// 正在刷新的图标</span>

- <span class="keyword">private</span> View refreshingView;

- <span class="comment">// 刷新结果图标</span>

- <span class="keyword">private</span> View refreshStateImageView;

- <span class="comment">// 刷新结果：成功或失败</span>

- <span class="keyword">private</span> TextView refreshStateTextView;

- 
- <span class="comment">// 上拉头</span>

- <span class="keyword">private</span> View loadmoreView;

- <span class="comment">// 上拉的箭头</span>

- <span class="keyword">private</span> View pullUpView;

- <span class="comment">// 正在加载的图标</span>

- <span class="keyword">private</span> View loadingView;

- <span class="comment">// 加载结果图标</span>

- <span class="keyword">private</span> View loadStateImageView;

- <span class="comment">// 加载结果：成功或失败</span>

- <span class="keyword">private</span> TextView loadStateTextView;

- 
- <span class="comment">// 实现了Pullable接口的View</span>

- <span class="keyword">private</span> View pullableView;

- <span class="comment">// 过滤多点触碰</span>

- <span class="keyword">private</span> <span class="keyword">int</span> mEvents;

- <span class="comment">// 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</span>

- <span class="keyword">private</span> <span class="keyword">boolean</span> canPullDown = <span class="keyword">true</span>;

- <span class="keyword">private</span> <span class="keyword">boolean</span> canPullUp = <span class="keyword">true</span>;

- 
- <span class="comment">/**</span>

- <span class="comment">     * 执行自动回滚的handler</span>

- <span class="comment">     */</span>

- Handler updateHandler = <span class="keyword">new</span> Handler()

- {

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">void</span> handleMessage(Message msg)

- {

- <span class="comment">// 回弹速度随下拉距离moveDeltaY增大而增大</span>

- MOVE_SPEED = (<span class="keyword">float</span>) (<span class="number">8</span> + <span class="number">5</span> * Math.tan(Math.PI / <span class="number">2</span>

- / getMeasuredHeight() * (pullDownY + Math.abs(pullUpY))));

- <span class="keyword">if</span> (!isTouch)

- {

- <span class="comment">// 正在刷新，且没有往上推的话则悬停，显示&#8221;正在刷新&#8230;&#8221;</span>

- <span class="keyword">if</span> (state == REFRESHING && pullDownY <= refreshDist)

- {

- pullDownY = refreshDist;

- timer.cancel();

- } <span class="keyword">else</span> <span class="keyword">if</span> (state == LOADING && -pullUpY <= loadmoreDist)

- {

- pullUpY = -loadmoreDist;

- timer.cancel();

- }

- 
- }

- <span class="keyword">if</span> (pullDownY > <span class="number"></span>)

- pullDownY -= MOVE_SPEED;

- <span class="keyword">else</span> <span class="keyword">if</span> (pullUpY < <span class="number"></span>)

- pullUpY += MOVE_SPEED;

- <span class="keyword">if</span> (pullDownY < <span class="number"></span>)

- {

- <span class="comment">// 已完成回弹</span>

- pullDownY = <span class="number"></span>;

- pullView.clearAnimation();

- <span class="comment">// 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</span>

- <span class="keyword">if</span> (state != REFRESHING && state != LOADING)

- changeState(INIT);

- timer.cancel();

- }

- <span class="keyword">if</span> (pullUpY > <span class="number"></span>)

- {

- <span class="comment">// 已完成回弹</span>

- pullUpY = <span class="number"></span>;

- pullUpView.clearAnimation();

- <span class="comment">// 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</span>

- <span class="keyword">if</span> (state != REFRESHING && state != LOADING)

- changeState(INIT);

- timer.cancel();

- }

- <span class="comment">// 刷新布局,会自动调用onLayout</span>

- requestLayout();

- }

- 
- };

- 
- <span class="keyword">public</span> <span class="keyword">void</span> setOnRefreshListener(OnRefreshListener listener)

- {

- mListener = listener;

- }

- 
- <span class="keyword">public</span> PullToRefreshLayout(Context context)

- {

- <span class="keyword">super</span>(context);

- initView(context);

- }

- 
- <span class="keyword">public</span> PullToRefreshLayout(Context context, AttributeSet attrs)

- {

- <span class="keyword">super</span>(context, attrs);

- initView(context);

- }

- 
- <span class="keyword">public</span> PullToRefreshLayout(Context context, AttributeSet attrs, <span class="keyword">int</span> defStyle)

- {

- <span class="keyword">super</span>(context, attrs, defStyle);

- initView(context);

- }

- 
- <span class="keyword">private</span> <span class="keyword">void</span> initView(Context context)

- {

- timer = <span class="keyword">new</span> MyTimer(updateHandler);

- rotateAnimation = (RotateAnimation) AnimationUtils.loadAnimation(

- context, R.anim.reverse_anim);

- refreshingAnimation = (RotateAnimation) AnimationUtils.loadAnimation(

- context, R.anim.rotating);

- <span class="comment">// 添加匀速转动动画</span>

- LinearInterpolator lir = <span class="keyword">new</span> LinearInterpolator();

- rotateAnimation.setInterpolator(lir);

- refreshingAnimation.setInterpolator(lir);

- }

- 
- <span class="keyword">private</span> <span class="keyword">void</span> hide()

- {

- timer.schedule(<span class="number">5</span>);

- }

- 
- <span class="comment">/**</span>

- <span class="comment">     * 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</span>

- <span class="comment">     */</span>

- <span class="comment">/**</span>

- <span class="comment">     * @param refreshResult</span>

- <span class="comment">     *            PullToRefreshLayout.SUCCEED代表成功，PullToRefreshLayout.FAIL代表失败</span>

- <span class="comment">     */</span>

- <span class="keyword">public</span> <span class="keyword">void</span> refreshFinish(<span class="keyword">int</span> refreshResult)

- {

- refreshingView.clearAnimation();

- refreshingView.setVisibility(View.GONE);

- <span class="keyword">switch</span> (refreshResult)

- {

- <span class="keyword">case</span> SUCCEED:

- <span class="comment">// 刷新成功</span>

- refreshStateImageView.setVisibility(View.VISIBLE);

- refreshStateTextView.setText(R.string.refresh_succeed);

- refreshStateImageView

- .setBackgroundResource(R.drawable.refresh_succeed);

- <span class="keyword">break</span>;

- <span class="keyword">case</span> FAIL:

- <span class="keyword">default</span>:

- <span class="comment">// 刷新失败</span>

- refreshStateImageView.setVisibility(View.VISIBLE);

- refreshStateTextView.setText(R.string.refresh_fail);

- refreshStateImageView

- .setBackgroundResource(R.drawable.refresh_failed);

- <span class="keyword">break</span>;

- }

- <span class="comment">// 刷新结果停留1秒</span>

- <span class="keyword">new</span> Handler()

- {

- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">void</span> handleMessage(Message msg)

- {

- changeState(DONE);

- hide();

- }

- }.sendEmptyMessageDelayed(<span class="number"></span>, <span class="number">1000</span>);

- }

- 
- <span class="comment">/**</span>

- <span class="comment">     * 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</span>

- <span class="comment">     * </span>

- <span class="comment">     * @param refreshResult</span>

- <span class="comment">     *            PullToRefreshLayout.SUCCEED代表成功，PullToRefreshLayout.FAIL代表失败</span>

- <span class="comment">     */</span>

- <span class="keyword">public</span> <span class="keyword">void</span> loadmoreFinish(<span class="keyword">int</span> refreshResult)

- {

- loadingView.clearAnimation();

- loadingView.setVisibility(View.GONE);

- <span class="keyword">switch</span> (refreshResult)

- {

- <span class="keyword">case</span> SUCCEED:

- <span class="comment">// 加载成功</span>

- loadStateImageView.setVisibility(View.VISIBLE);

- loadStateTextView.setText(R.string.load_succeed);

- loadStateImageView.setBackgroundResource(R.drawable.load_succeed);

- <span class="keyword">break</span>;

- <span class="keyword">case</span> FAIL:

- <span class="keyword">default</span>:

- <span class="comment">// 加载失败</span>

- loadStateImageView.setVisibility(View.VISIBLE);

- loadStateTextView.setText(R.string.load_fail);

- loadStateImageView.setBackgroundResource(R.drawable.load_failed);

- <span class="keyword">break</span>;

- }

- <span class="comment">// 刷新结果停留1秒</span>

- <span class="keyword">new</span> Handler()

- {

- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">void</span> handleMessage(Message msg)

- {

- changeState(DONE);

- hide();

- }

- }.sendEmptyMessageDelayed(<span class="number"></span>, <span class="number">1000</span>);

- }

- 
- <span class="keyword">private</span> <span class="keyword">void</span> changeState(<span class="keyword">int</span> to)

- {

- state = to;

- <span class="keyword">switch</span> (state)

- {

- <span class="keyword">case</span> INIT:

- <span class="comment">// 下拉布局初始状态</span>

- refreshStateImageView.setVisibility(View.GONE);

- refreshStateTextView.setText(R.string.pull_to_refresh);

- pullView.clearAnimation();

- pullView.setVisibility(View.VISIBLE);

- <span class="comment">// 上拉布局初始状态</span>

- loadStateImageView.setVisibility(View.GONE);

- loadStateTextView.setText(R.string.pullup_to_load);

- pullUpView.clearAnimation();

- pullUpView.setVisibility(View.VISIBLE);

- <span class="keyword">break</span>;

- <span class="keyword">case</span> RELEASE_TO_REFRESH:

- <span class="comment">// 释放刷新状态</span>

- refreshStateTextView.setText(R.string.release_to_refresh);

- pullView.startAnimation(rotateAnimation);

- <span class="keyword">break</span>;

- <span class="keyword">case</span> REFRESHING:

- <span class="comment">// 正在刷新状态</span>

- pullView.clearAnimation();

- refreshingView.setVisibility(View.VISIBLE);

- pullView.setVisibility(View.INVISIBLE);

- refreshingView.startAnimation(refreshingAnimation);

- refreshStateTextView.setText(R.string.refreshing);

- <span class="keyword">break</span>;

- <span class="keyword">case</span> RELEASE_TO_LOAD:

- <span class="comment">// 释放加载状态</span>

- loadStateTextView.setText(R.string.release_to_load);

- pullUpView.startAnimation(rotateAnimation);

- <span class="keyword">break</span>;

- <span class="keyword">case</span> LOADING:

- <span class="comment">// 正在加载状态</span>

- pullUpView.clearAnimation();

- loadingView.setVisibility(View.VISIBLE);

- pullUpView.setVisibility(View.INVISIBLE);

- loadingView.startAnimation(refreshingAnimation);

- loadStateTextView.setText(R.string.loading);

- <span class="keyword">break</span>;

- <span class="keyword">case</span> DONE:

- <span class="comment">// 刷新或加载完毕，啥都不做</span>

- <span class="keyword">break</span>;

- }

- }

- 
- <span class="comment">/**</span>

- <span class="comment">     * 不限制上拉或下拉</span>

- <span class="comment">     */</span>

- <span class="keyword">private</span> <span class="keyword">void</span> releasePull()

- {

- canPullDown = <span class="keyword">true</span>;

- canPullUp = <span class="keyword">true</span>;

- }

- 
- <span class="comment">/*</span>

- <span class="comment">     * （非 Javadoc）由父控件决定是否分发事件，防止事件冲突</span>

- <span class="comment">     * </span>

- <span class="comment">     * @see android.view.ViewGroup#dispatchTouchEvent(android.view.MotionEvent)</span>

- <span class="comment">     */</span>

- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> dispatchTouchEvent(MotionEvent ev)

- {

- <span class="keyword">switch</span> (ev.getActionMasked())

- {

- <span class="keyword">case</span> MotionEvent.ACTION_DOWN:

- downY = ev.getY();

- lastY = downY;

- timer.cancel();

- mEvents = <span class="number"></span>;

- releasePull();

- <span class="keyword">break</span>;

- <span class="keyword">case</span> MotionEvent.ACTION_POINTER_DOWN:

- <span class="keyword">case</span> MotionEvent.ACTION_POINTER_UP:

- <span class="comment">// 过滤多点触碰</span>

- mEvents = &#8211;<span class="number">1</span>;

- <span class="keyword">break</span>;

- <span class="keyword">case</span> MotionEvent.ACTION_MOVE:

- <span class="keyword">if</span> (mEvents == <span class="number"></span>)

- {

- <span class="keyword">if</span> (((Pullable) pullableView).canPullDown() && canPullDown

- && state != LOADING)

- {

- <span class="comment">// 可以下拉，正在加载时不能下拉</span>

- <span class="comment">// 对实际滑动距离做缩小，造成用力拉的感觉</span>

- pullDownY = pullDownY + (ev.getY() &#8211; lastY) / radio;

- <span class="keyword">if</span> (pullDownY < <span class="number"></span>)

- {

- pullDownY = <span class="number"></span>;

- canPullDown = <span class="keyword">false</span>;

- canPullUp = <span class="keyword">true</span>;

- }

- <span class="keyword">if</span> (pullDownY > getMeasuredHeight())

- pullDownY = getMeasuredHeight();

- <span class="keyword">if</span> (state == REFRESHING)

- {

- <span class="comment">// 正在刷新的时候触摸移动</span>

- isTouch = <span class="keyword">true</span>;

- }

- } <span class="keyword">else</span> <span class="keyword">if</span> (((Pullable) pullableView).canPullUp() && canPullUp

- && state != REFRESHING)

- {

- <span class="comment">// 可以上拉，正在刷新时不能上拉</span>

- pullUpY = pullUpY + (ev.getY() &#8211; lastY) / radio;

- <span class="keyword">if</span> (pullUpY > <span class="number"></span>)

- {

- pullUpY = <span class="number"></span>;

- canPullDown = <span class="keyword">true</span>;

- canPullUp = <span class="keyword">false</span>;

- }

- <span class="keyword">if</span> (pullUpY < -getMeasuredHeight())

- pullUpY = -getMeasuredHeight();

- <span class="keyword">if</span> (state == LOADING)

- {

- <span class="comment">// 正在加载的时候触摸移动</span>

- isTouch = <span class="keyword">true</span>;

- }

- } <span class="keyword">else</span>

- releasePull();

- } <span class="keyword">else</span>

- mEvents = <span class="number"></span>;

- lastY = ev.getY();

- <span class="comment">// 根据下拉距离改变比例</span>

- radio = (<span class="keyword">float</span>) (<span class="number">2</span> + <span class="number">2</span> * Math.tan(Math.PI / <span class="number">2</span> / getMeasuredHeight()

- * (pullDownY + Math.abs(pullUpY))));

- requestLayout();

- <span class="keyword">if</span> (pullDownY <= refreshDist

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>                    </span>&& (state == RELEASE_TO_REFRESH || state == DONE)) {

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>                </span><span class="comment">// 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</span>

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>                </span>changeState(INIT);

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>            </span>}

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>            </span><span class="keyword">if</span> (pullDownY >= refreshDist && (state == INIT || state == DONE)) {

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>                </span><span class="comment">// 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</span>

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>                </span>changeState(RELEASE_TO_REFRESH);

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>            </span>}

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>            </span><span class="comment">// 下面是判断上拉加载的，同上，注意pullUpY是负值</span>

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>            </span><span class="keyword">if</span> (-pullUpY <= loadmoreDist

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>                    </span>&& (state == RELEASE_TO_LOAD || state == DONE)) {

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>                </span>changeState(INIT);

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>            </span>}

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>            </span><span class="keyword">if</span> (-pullUpY >= loadmoreDist && (state == INIT || state == DONE)) {

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>                </span>changeState(RELEASE_TO_LOAD);

- <span style=<span class="string">&#8220;white-space:pre&#8221;</span>>            </span>}

- <span class="comment">// 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 +</span>

- <span class="comment">// Math.abs(pullUpY))就可以不对当前状态作区分了</span>

- <span class="keyword">if</span> ((pullDownY + Math.abs(pullUpY)) > <span class="number">8</span>)

- {

- <span class="comment">// 防止下拉过程中误触发长按事件和点击事件</span>

- ev.setAction(MotionEvent.ACTION_CANCEL);

- }

- <span class="keyword">break</span>;

- <span class="keyword">case</span> MotionEvent.ACTION_UP:

- <span class="keyword">if</span> (pullDownY > refreshDist || -pullUpY > loadmoreDist)

- <span class="comment">// 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</span>

- isTouch = <span class="keyword">false</span>;

- <span class="keyword">if</span> (state == RELEASE_TO_REFRESH)

- {

- changeState(REFRESHING);

- <span class="comment">// 刷新操作</span>

- <span class="keyword">if</span> (mListener != <span class="keyword">null</span>)

- mListener.onRefresh(<span class="keyword">this</span>);

- } <span class="keyword">else</span> <span class="keyword">if</span> (state == RELEASE_TO_LOAD)

- {

- changeState(LOADING);

- <span class="comment">// 加载操作</span>

- <span class="keyword">if</span> (mListener != <span class="keyword">null</span>)

- mListener.onLoadMore(<span class="keyword">this</span>);

- }

- hide();

- <span class="keyword">default</span>:

- <span class="keyword">break</span>;

- }

- <span class="comment">// 事件分发交给父类</span>

- <span class="keyword">super</span>.dispatchTouchEvent(ev);

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="keyword">private</span> <span class="keyword">void</span> initView()

- {

- <span class="comment">// 初始化下拉布局</span>

- 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);

- <span class="comment">// 初始化上拉布局</span>

- 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);

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">protected</span> <span class="keyword">void</span> onLayout(<span class="keyword">boolean</span> changed, <span class="keyword">int</span> l, <span class="keyword">int</span> t, <span class="keyword">int</span> r, <span class="keyword">int</span> b)

- {

- <span class="keyword">if</span> (!isLayout)

- {

- <span class="comment">// 这里是第一次进来的时候做一些初始化</span>

- refreshView = getChildAt(<span class="number"></span>);

- pullableView = getChildAt(<span class="number">1</span>);

- loadmoreView = getChildAt(<span class="number">2</span>);

- isLayout = <span class="keyword">true</span>;

- initView();

- refreshDist = ((ViewGroup) refreshView).getChildAt(<span class="number"></span>)

- .getMeasuredHeight();

- loadmoreDist = ((ViewGroup) loadmoreView).getChildAt(<span class="number"></span>)

- .getMeasuredHeight();

- }

- <span class="comment">// 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</span>

- refreshView.layout(<span class="number"></span>,

- (<span class="keyword">int</span>) (pullDownY + pullUpY) &#8211; refreshView.getMeasuredHeight(),

- refreshView.getMeasuredWidth(), (<span class="keyword">int</span>) (pullDownY + pullUpY));

- pullableView.layout(<span class="number"></span>, (<span class="keyword">int</span>) (pullDownY + pullUpY),

- pullableView.getMeasuredWidth(), (<span class="keyword">int</span>) (pullDownY + pullUpY)

- + pullableView.getMeasuredHeight());

- loadmoreView.layout(<span class="number"></span>,

- (<span class="keyword">int</span>) (pullDownY + pullUpY) + pullableView.getMeasuredHeight(),

- loadmoreView.getMeasuredWidth(),

- (<span class="keyword">int</span>) (pullDownY + pullUpY) + pullableView.getMeasuredHeight()

- + loadmoreView.getMeasuredHeight());

- }

- 
- <span class="keyword">class</span> MyTimer

- {

- <span class="keyword">private</span> Handler handler;

- <span class="keyword">private</span> Timer timer;

- <span class="keyword">private</span> MyTask mTask;

- 
- <span class="keyword">public</span> MyTimer(Handler handler)

- {

- <span class="keyword">this</span>.handler = handler;

- timer = <span class="keyword">new</span> Timer();

- }

- 
- <span class="keyword">public</span> <span class="keyword">void</span> schedule(<span class="keyword">long</span> period)

- {

- <span class="keyword">if</span> (mTask != <span class="keyword">null</span>)

- {

- mTask.cancel();

- mTask = <span class="keyword">null</span>;

- }

- mTask = <span class="keyword">new</span> MyTask(handler);

- timer.schedule(mTask, <span class="number"></span>, period);

- }

- 
- <span class="keyword">public</span> <span class="keyword">void</span> cancel()

- {

- <span class="keyword">if</span> (mTask != <span class="keyword">null</span>)

- {

- mTask.cancel();

- mTask = <span class="keyword">null</span>;

- }

- }

- 
- <span class="keyword">class</span> MyTask <span class="keyword">extends</span> TimerTask

- {

- <span class="keyword">private</span> Handler handler;

- 
- <span class="keyword">public</span> MyTask(Handler handler)

- {

- <span class="keyword">this</span>.handler = handler;

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">void</span> run()

- {

- handler.obtainMessage().sendToTarget();

- }

- 
- }

- }

- 
- <span class="comment">/**</span>

- <span class="comment">     * 刷新加载回调接口</span>

- <span class="comment">     * </span>

- <span class="comment">     * @author chenjing</span>

- <span class="comment">     * </span>

- <span class="comment">     */</span>

- <span class="keyword">public</span> <span class="keyword">interface</span> OnRefreshListener

- {

- <span class="comment">/**</span>

- <span class="comment">         * 刷新操作</span>

- <span class="comment">         */</span>

- <span class="keyword">void</span> onRefresh(PullToRefreshLayout pullToRefreshLayout);

- 
- <span class="comment">/**</span>

- <span class="comment">         * 加载操作</span>

- <span class="comment">         */</span>

- <span class="keyword">void</span> onLoadMore(PullToRefreshLayout pullToRefreshLayout);

- }

- 
- }

上面就是整个布局的代码，并不是很难。

下面看各个View对Pullable接口的实现，ListView和GridView还有ExpandableListView的判断方法是一样的：

PullableListView：

**[java]** [view plain](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)[copy](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)

  <div>
    <embed id="ZeroClipboardMovie_3" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_3">
    </embed>
  </div>
</div>

- <span class="keyword">package</span> com.jingchen.pulltorefresh.pullableview;

- 
- <span class="keyword">import</span> android.content.Context;

- <span class="keyword">import</span> android.util.AttributeSet;

- <span class="keyword">import</span> android.util.Log;

- <span class="keyword">import</span> android.widget.ListView;

- 
- <span class="keyword">public</span> <span class="keyword">class</span> PullableListView <span class="keyword">extends</span> ListView <span class="keyword">implements</span> Pullable

- {

- 
- <span class="keyword">public</span> PullableListView(Context context)

- {

- <span class="keyword">super</span>(context);

- }

- 
- <span class="keyword">public</span> PullableListView(Context context, AttributeSet attrs)

- {

- <span class="keyword">super</span>(context, attrs);

- }

- 
- <span class="keyword">public</span> PullableListView(Context context, AttributeSet attrs, <span class="keyword">int</span> defStyle)

- {

- <span class="keyword">super</span>(context, attrs, defStyle);

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullDown()

- {

- <span class="keyword">if</span> (getCount() == <span class="number"></span>)

- {

- <span class="comment">// 没有item的时候也可以下拉刷新</span>

- <span class="keyword">return</span> <span class="keyword">true</span>;

- } <span class="keyword">else</span> <span class="keyword">if</span> (getFirstVisiblePosition() == <span class="number"></span>

- && getChildAt(<span class="number"></span>).getTop() >= <span class="number"></span>)

- {

- <span class="comment">// 滑到ListView的顶部了</span>

- <span class="keyword">return</span> <span class="keyword">true</span>;

- } <span class="keyword">else</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullUp()

- {

- <span class="keyword">if</span> (getCount() == <span class="number"></span>)

- {

- <span class="comment">// 没有item的时候也可以上拉加载</span>

- <span class="keyword">return</span> <span class="keyword">true</span>;

- } <span class="keyword">else</span> <span class="keyword">if</span> (getLastVisiblePosition() == (getCount() &#8211; <span class="number">1</span>))

- {

- <span class="comment">// 滑到底部了</span>

- <span class="keyword">if</span> (getChildAt(getLastVisiblePosition() &#8211; getFirstVisiblePosition()) != <span class="keyword">null</span>

- && getChildAt(

- getLastVisiblePosition()

- &#8211; getFirstVisiblePosition()).getBottom() <= getMeasuredHeight())

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- }

PullableExpandableListView：

**[java]** [view plain](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)[copy](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)

  <div>
    <embed id="ZeroClipboardMovie_4" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_4">
    </embed>
  </div>
</div>

- <span class="keyword">package</span> com.jingchen.pulltorefresh.pullableview;

- 
- <span class="keyword">import</span> android.content.Context;

- <span class="keyword">import</span> android.util.AttributeSet;

- <span class="keyword">import</span> android.widget.ExpandableListView;

- 
- <span class="keyword">public</span> <span class="keyword">class</span> PullableExpandableListView <span class="keyword">extends</span> ExpandableListView <span class="keyword">implements</span>

- Pullable

- {

- 
- <span class="keyword">public</span> PullableExpandableListView(Context context)

- {

- <span class="keyword">super</span>(context);

- }

- 
- <span class="keyword">public</span> PullableExpandableListView(Context context, AttributeSet attrs)

- {

- <span class="keyword">super</span>(context, attrs);

- }

- 
- <span class="keyword">public</span> PullableExpandableListView(Context context, AttributeSet attrs,

- <span class="keyword">int</span> defStyle)

- {

- <span class="keyword">super</span>(context, attrs, defStyle);

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullDown()

- {

- <span class="keyword">if</span> (getCount() == <span class="number"></span>)

- {

- <span class="comment">// 没有item的时候也可以下拉刷新</span>

- <span class="keyword">return</span> <span class="keyword">true</span>;

- } <span class="keyword">else</span> <span class="keyword">if</span> (getFirstVisiblePosition() == <span class="number"></span>

- && getChildAt(<span class="number"></span>).getTop() >= <span class="number"></span>)

- {

- <span class="comment">// 滑到顶部了</span>

- <span class="keyword">return</span> <span class="keyword">true</span>;

- } <span class="keyword">else</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullUp()

- {

- <span class="keyword">if</span> (getCount() == <span class="number"></span>)

- {

- <span class="comment">// 没有item的时候也可以上拉加载</span>

- <span class="keyword">return</span> <span class="keyword">true</span>;

- } <span class="keyword">else</span> <span class="keyword">if</span> (getLastVisiblePosition() == (getCount() &#8211; <span class="number">1</span>))

- {

- <span class="comment">// 滑到底部了</span>

- <span class="keyword">if</span> (getChildAt(getLastVisiblePosition() &#8211; getFirstVisiblePosition()) != <span class="keyword">null</span>

- && getChildAt(

- getLastVisiblePosition()

- &#8211; getFirstVisiblePosition()).getBottom() <= getMeasuredHeight())

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- }

PullableGridView：

**[java]** [view plain](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)[copy](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)

  <div>
    <embed id="ZeroClipboardMovie_5" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_5">
    </embed>
  </div>
</div>

- <span class="keyword">package</span> com.jingchen.pulltorefresh.pullableview;

- 
- <span class="keyword">import</span> android.content.Context;

- <span class="keyword">import</span> android.util.AttributeSet;

- <span class="keyword">import</span> android.widget.GridView;

- 
- <span class="keyword">public</span> <span class="keyword">class</span> PullableGridView <span class="keyword">extends</span> GridView <span class="keyword">implements</span> Pullable

- {

- 
- <span class="keyword">public</span> PullableGridView(Context context)

- {

- <span class="keyword">super</span>(context);

- }

- 
- <span class="keyword">public</span> PullableGridView(Context context, AttributeSet attrs)

- {

- <span class="keyword">super</span>(context, attrs);

- }

- 
- <span class="keyword">public</span> PullableGridView(Context context, AttributeSet attrs, <span class="keyword">int</span> defStyle)

- {

- <span class="keyword">super</span>(context, attrs, defStyle);

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullDown()

- {

- <span class="keyword">if</span> (getCount() == <span class="number"></span>)

- {

- <span class="comment">// 没有item的时候也可以下拉刷新</span>

- <span class="keyword">return</span> <span class="keyword">true</span>;

- } <span class="keyword">else</span> <span class="keyword">if</span> (getFirstVisiblePosition() == <span class="number"></span>

- && getChildAt(<span class="number"></span>).getTop() >= <span class="number"></span>)

- {

- <span class="comment">// 滑到顶部了</span>

- <span class="keyword">return</span> <span class="keyword">true</span>;

- } <span class="keyword">else</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullUp()

- {

- <span class="keyword">if</span> (getCount() == <span class="number"></span>)

- {

- <span class="comment">// 没有item的时候也可以上拉加载</span>

- <span class="keyword">return</span> <span class="keyword">true</span>;

- } <span class="keyword">else</span> <span class="keyword">if</span> (getLastVisiblePosition() == (getCount() &#8211; <span class="number">1</span>))

- {

- <span class="comment">// 滑到底部了</span>

- <span class="keyword">if</span> (getChildAt(getLastVisiblePosition() &#8211; getFirstVisiblePosition()) != <span class="keyword">null</span>

- && getChildAt(

- getLastVisiblePosition()

- &#8211; getFirstVisiblePosition()).getBottom() <= getMeasuredHeight())

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- }

PullableScrollView：

**[java]** [view plain](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)[copy](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)

  <div>
    <embed id="ZeroClipboardMovie_6" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_6">
    </embed>
  </div>
</div>

- <span class="keyword">package</span> com.jingchen.pulltorefresh.pullableview;

- 
- <span class="keyword">import</span> android.content.Context;

- <span class="keyword">import</span> android.util.AttributeSet;

- <span class="keyword">import</span> android.widget.ScrollView;

- 
- <span class="keyword">public</span> <span class="keyword">class</span> PullableScrollView <span class="keyword">extends</span> ScrollView <span class="keyword">implements</span> Pullable

- {

- 
- <span class="keyword">public</span> PullableScrollView(Context context)

- {

- <span class="keyword">super</span>(context);

- }

- 
- <span class="keyword">public</span> PullableScrollView(Context context, AttributeSet attrs)

- {

- <span class="keyword">super</span>(context, attrs);

- }

- 
- <span class="keyword">public</span> PullableScrollView(Context context, AttributeSet attrs, <span class="keyword">int</span> defStyle)

- {

- <span class="keyword">super</span>(context, attrs, defStyle);

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullDown()

- {

- <span class="keyword">if</span> (getScrollY() == <span class="number"></span>)

- <span class="keyword">return</span> <span class="keyword">true</span>;

- <span class="keyword">else</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullUp()

- {

- <span class="keyword">if</span> (getScrollY() >= (getChildAt(<span class="number"></span>).getHeight() &#8211; getMeasuredHeight()))

- <span class="keyword">return</span> <span class="keyword">true</span>;

- <span class="keyword">else</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- }

PullableWebView：

**[java]** [view plain](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)[copy](http://blog.csdn.net/zhongkejingwang/article/details/38868463#)

  <div>
    <embed id="ZeroClipboardMovie_7" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_7">
    </embed>
  </div>
</div>

- <span class="keyword">package</span> com.jingchen.pulltorefresh.pullableview;

- 
- <span class="keyword">import</span> android.content.Context;

- <span class="keyword">import</span> android.util.AttributeSet;

- <span class="keyword">import</span> android.webkit.WebView;

- 
- <span class="keyword">public</span> <span class="keyword">class</span> PullableWebView <span class="keyword">extends</span> WebView <span class="keyword">implements</span> Pullable

- {

- 
- <span class="keyword">public</span> PullableWebView(Context context)

- {

- <span class="keyword">super</span>(context);

- }

- 
- <span class="keyword">public</span> PullableWebView(Context context, AttributeSet attrs)

- {

- <span class="keyword">super</span>(context, attrs);

- }

- 
- <span class="keyword">public</span> PullableWebView(Context context, AttributeSet attrs, <span class="keyword">int</span> defStyle)

- {

- <span class="keyword">super</span>(context, attrs, defStyle);

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullDown()

- {

- <span class="keyword">if</span> (getScrollY() == <span class="number"></span>)

- <span class="keyword">return</span> <span class="keyword">true</span>;

- <span class="keyword">else</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="annotation">@Override</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> canPullUp()

- {

- <span class="keyword">if</span> (getScrollY() >= getContentHeight() * getScale()

- &#8211; getMeasuredHeight())

- <span class="keyword">return</span> <span class="keyword">true</span>;

- <span class="keyword">else</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- }

ImageView和TextView就不贴了，我直接在方法里返回了true。

OK了，整个demo的代码有点多，就不贴了。

源码下载

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