Android SwipeRefreshLayout下拉刷新与上拉加载+滑动删除

最新推荐文章于 2025-05-28 10:26:52 发布

转载最新推荐文章于 2025-05-28 10:26:52 发布 · 2.5k 阅读

文章标签：

#Android #SwipeRefreshLayout #下拉刷新与上拉加载 #+ #滑动删除

本文介绍如何使用SwipeRefreshLayout实现下拉刷新、上拉加载及滑动删除功能。文章提供了两种上拉加载实现方式，并解决了滑动删除与其他操作的冲突。

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SwipeRefreshLayout–Google官方提出的下拉刷新控件，广泛应用在各种APP中。一直想弄一个既能支持下拉刷新，又能够上拉加载，同时还能实现类似于QQ的滑动删除效果。上网找了很多资料，最后达到了下面的效果：
这里写图片描述

参考资料：
SwipeRefreshLayout的上拉加载与下拉刷新：

http://blog.youkuaiyun.com/u012036813/article/details/38959507

Listview的滑动删除：

http://blog.youkuaiyun.com/lmj623565791/article/details/22961279

Android事件传递机制：

http://blog.youkuaiyun.com/yanzi1225627/article/details/22592831

接下来看看具体实现过程。

1.界面布局：

<<span class="hljs-keyword">com</span><span class="hljs-preprocessor">.example</span><span class="hljs-preprocessor">.swiperefreshlayoutdemo</span><span class="hljs-preprocessor">.RefreshLayout</span>
        xmlns:android=<span class="hljs-string">"http://schemas.android.com/apk/res/android"</span>
        android:id=<span class="hljs-string">"@+id/swipe_container"</span>
        android:layout_width=<span class="hljs-string">"match_parent"</span>
        android:layout_height=<span class="hljs-string">"match_parent"</span> >

        <<span class="hljs-keyword">com</span><span class="hljs-preprocessor">.example</span><span class="hljs-preprocessor">.swiperefreshlayoutdemo</span><span class="hljs-preprocessor">.QQListView</span>
            android:id=<span class="hljs-string">"@+id/list"</span>
            android:layout_width=<span class="hljs-string">"match_parent"</span>
            android:layout_height=<span class="hljs-string">"wrap_content"</span> >
        </<span class="hljs-keyword">com</span><span class="hljs-preprocessor">.example</span><span class="hljs-preprocessor">.swiperefreshlayoutdemo</span><span class="hljs-preprocessor">.QQListView</span>>
    </<span class="hljs-keyword">com</span><span class="hljs-preprocessor">.example</span><span class="hljs-preprocessor">.swiperefreshlayoutdemo</span><span class="hljs-preprocessor">.RefreshLayout</span>>

因为要实现上拉加载以及滑动删除，所以用的都是自定义的RefreshLayout以及Listview。 
<strong>2.代码实现：</strong>

SwipeRefreshLayout的上拉加载实现有两种方法，一种是实现滑动监听，当滑动到底部时实现加载更多功能；一种是通过事件传递机制监听上拉动作，然后实现加载更多功能。先看第一种加载原理：

自定义的SwipeRefreshLayout：

<span class="hljs-comment">//继承自SwipeRefreshLayout,从而实现滑动到底部时上拉加载更多的功能.</span>

<span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">RefreshLayout</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">SwipeRefreshLayout</span> <span class="hljs-keyword">implements</span>    <span class="hljs-title">OnScrollListener</span> {</span>

    <span class="hljs-comment">// listview实例</span>
    <span class="hljs-keyword">private</span> ListView mListView;
    <span class="hljs-comment">// 上拉接口监听器, 到了最底部的上拉加载操作</span>
    <span class="hljs-keyword">private</span> OnLoadListener mOnLoadListener;
    <span class="hljs-comment">// ListView的加载中footer</span>
    <span class="hljs-keyword">private</span> View mListViewFooter;
    <span class="hljs-comment">// 是否在加载中 ( 上拉加载更多 )</span>
    <span class="hljs-keyword">private</span> <span class="hljs-keyword">boolean</span> isLoading = <span class="hljs-keyword">false</span>;

    <span class="hljs-keyword">public</span> <span class="hljs-title">RefreshLayout</span>(Context context) {
        <span class="hljs-keyword">this</span>(context, <span class="hljs-keyword">null</span>);
    }

    <span class="hljs-keyword">public</span> <span class="hljs-title">RefreshLayout</span>(Context context, AttributeSet attrs) {
        <span class="hljs-keyword">super</span>(context, attrs);
        <span class="hljs-comment">//一个圆形进度条</span>
        mListViewFooter = LayoutInflater.from(context).inflate(
                R.layout.listview_footer, <span class="hljs-keyword">null</span>, <span class="hljs-keyword">false</span>);
    }

    <span class="hljs-annotation">@Override</span>
    <span class="hljs-keyword">protected</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onLayout</span>(<span class="hljs-keyword">boolean</span> changed, <span class="hljs-keyword">int</span> left, <span class="hljs-keyword">int</span> top, <span class="hljs-keyword">int</span> right,
            <span class="hljs-keyword">int</span> bottom) {
        <span class="hljs-keyword">super</span>.onLayout(changed, left, top, right, bottom);
        <span class="hljs-comment">// 初始化ListView对象</span>
        <span class="hljs-keyword">if</span> (mListView == <span class="hljs-keyword">null</span>) {
            getListView();
        }
    }

    <span class="hljs-comment">// 获取ListView对象</span>
    <span class="hljs-keyword">private</span> <span class="hljs-keyword">void</span> <span class="hljs-title">getListView</span>() {
        <span class="hljs-keyword">int</span> childs = getChildCount();
        <span class="hljs-keyword">if</span> (childs > <span class="hljs-number">0</span>) {
            View childView = getChildAt(<span class="hljs-number">0</span>);
            <span class="hljs-keyword">if</span> (childView <span class="hljs-keyword">instanceof</span> ListView) {
                mListView = (ListView) childView;
                <span class="hljs-comment">// 设置滚动监听器给ListView</span>
                mListView.setOnScrollListener(<span class="hljs-keyword">this</span>);
            }
        }
    }



    <span class="hljs-comment">// 设置加载状态,添加或者移除加载更多圆形进度条</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setLoading</span>(<span class="hljs-keyword">boolean</span> loading) {
        isLoading = loading;
        <span class="hljs-keyword">if</span> (isLoading) {
            mListView.addFooterView(mListViewFooter);
        } <span class="hljs-keyword">else</span> {
            mListView.removeFooterView(mListViewFooter);

        }
    }

    <span class="hljs-comment">//设置监听器</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setOnLoadListener</span>(OnLoadListener loadListener) {
        mOnLoadListener = loadListener;
    }

    <span class="hljs-annotation">@Override</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onScrollStateChanged</span>(AbsListView view, <span class="hljs-keyword">int</span> scrollState) {

    }

    <span class="hljs-annotation">@Override</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onScroll</span>(AbsListView view, <span class="hljs-keyword">int</span> firstVisibleItem,
            <span class="hljs-keyword">int</span> visibleItemCount, <span class="hljs-keyword">int</span> totalItemCount) {

        <span class="hljs-comment">// 判断是否到了最底部，并且不是在加载数据的状态</span>
        <span class="hljs-keyword">if</span> (mListView.getLastVisiblePosition() == mListView.getAdapter()
                .getCount() - <span class="hljs-number">1</span> && isLoading == <span class="hljs-keyword">false</span>) {
            <span class="hljs-comment">// 首先设置加载状态</span>
            setLoading(<span class="hljs-keyword">true</span>);
            <span class="hljs-comment">// 调用加载数据的方法</span>
            mOnLoadListener.onLoad();

        }

    }

    <span class="hljs-comment">// 加载更多的接口</span>
    <span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">interface</span> <span class="hljs-title">OnLoadListener</span> {</span>
        <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onLoad</span>();
    }
}

注释写的很清楚，实现滑动监听，然后初始化listview，写好加载任务接口与方法。在滑动监听方法里面，有几个参数注意一下： 
<strong>firstVisibleItem</strong> 表示在当前屏幕显示的第一个listItem在整个listView里面的位置（下标从0开始） 
<strong>visibleItemCount</strong>表示在现时屏幕可以见到的ListItem(部分显示的ListItem也算)总数 
<strong>totalItemCount</strong>表示ListView的ListItem总数 
<strong>listView.getLastVisiblePosition()</strong>表示在现时屏幕最后一个ListItem (最后ListItem要完全显示出来才算)在整个ListView的位置（下标从0开始）
刚开始只判断是否滑动到了最底部，没有对加载状态进行判断，导致程序运行崩溃，在最底部加载数据时会一直加载。后来加上判断，默认不加载数据，isLoading==false，滑动到最底部加载数据时，设置为true，当加载完成以后，设置为false，加载完毕。

接下来是第二种加载原理：

<span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">RefreshLayout</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">SwipeRefreshLayout</span> {</span>

    <span class="hljs-comment">// listview实例</span>
    <span class="hljs-keyword">private</span> ListView mListView;
    <span class="hljs-comment">// 上拉接口监听器, 到了最底部的上拉加载操作</span>
    <span class="hljs-keyword">private</span> OnLoadListener mOnLoadListener;
    <span class="hljs-comment">// ListView的加载中footer</span>
    <span class="hljs-keyword">private</span> View mListViewFooter;
    <span class="hljs-comment">// 是否在加载中 ( 上拉加载更多 )</span>
    <span class="hljs-keyword">private</span> <span class="hljs-keyword">boolean</span> isLoading = <span class="hljs-keyword">false</span>;

    <span class="hljs-comment">// 按下时的y坐标</span>
    <span class="hljs-keyword">private</span> <span class="hljs-keyword">int</span> mYDown;
    <span class="hljs-comment">// 抬起时的y坐标</span>
    <span class="hljs-keyword">private</span> <span class="hljs-keyword">int</span> mLastY;
    <span class="hljs-comment">// 滑动到最下面时的上拉操作</span>
    <span class="hljs-keyword">private</span> <span class="hljs-keyword">int</span> mTouchSlop;

    <span class="hljs-keyword">public</span> <span class="hljs-title">RefreshLayout</span>(Context context) {
        <span class="hljs-keyword">this</span>(context, <span class="hljs-keyword">null</span>);
    }

    <span class="hljs-keyword">public</span> <span class="hljs-title">RefreshLayout</span>(Context context, AttributeSet attrs) {
        <span class="hljs-keyword">super</span>(context, attrs);

        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
        mListViewFooter = LayoutInflater.from(context).inflate(
                R.layout.listview_footer, <span class="hljs-keyword">null</span>, <span class="hljs-keyword">false</span>);
    }

    <span class="hljs-annotation">@Override</span>
    <span class="hljs-keyword">protected</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onLayout</span>(<span class="hljs-keyword">boolean</span> changed, <span class="hljs-keyword">int</span> left, <span class="hljs-keyword">int</span> top, <span class="hljs-keyword">int</span> right,
            <span class="hljs-keyword">int</span> bottom) {
        <span class="hljs-keyword">super</span>.onLayout(changed, left, top, right, bottom);
        <span class="hljs-comment">// 初始化ListView对象</span>
        <span class="hljs-keyword">if</span> (mListView == <span class="hljs-keyword">null</span>) {
            getListView();
        }
    }

    <span class="hljs-comment">// 获取ListView对象</span>
    <span class="hljs-keyword">private</span> <span class="hljs-keyword">void</span> <span class="hljs-title">getListView</span>() {
        <span class="hljs-keyword">int</span> childs = getChildCount();
        <span class="hljs-keyword">if</span> (childs > <span class="hljs-number">0</span>) {
            View childView = getChildAt(<span class="hljs-number">0</span>);
            <span class="hljs-keyword">if</span> (childView <span class="hljs-keyword">instanceof</span> ListView) {
                mListView = (ListView) childView;
            }
        }
    }

    <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">dispatchTouchEvent</span>(MotionEvent event) {
        <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> action = event.getAction();

        <span class="hljs-keyword">switch</span> (action) {
        <span class="hljs-keyword">case</span> MotionEvent.ACTION_DOWN:
            <span class="hljs-comment">// 按下</span>
            mYDown = (<span class="hljs-keyword">int</span>) event.getRawY();
            <span class="hljs-keyword">break</span>;

        <span class="hljs-keyword">case</span> MotionEvent.ACTION_MOVE:
            <span class="hljs-comment">// 移动</span>
            mLastY = (<span class="hljs-keyword">int</span>) event.getRawY();
            <span class="hljs-keyword">break</span>;

        <span class="hljs-keyword">case</span> MotionEvent.ACTION_UP:
            <span class="hljs-comment">// 抬起</span>
            <span class="hljs-keyword">if</span> ((mYDown - mLastY) >= mTouchSlop && isLoading == <span class="hljs-keyword">false</span>) {
                <span class="hljs-comment">// 设置状态</span>
                setLoading(<span class="hljs-keyword">true</span>);
                <span class="hljs-comment">//</span>
                mOnLoadListener.onLoad();
            }
            <span class="hljs-keyword">break</span>;
        <span class="hljs-keyword">default</span>:
            <span class="hljs-keyword">break</span>;
        }

        <span class="hljs-keyword">return</span> <span class="hljs-keyword">super</span>.dispatchTouchEvent(event);
    }

    <span class="hljs-comment">// 设置加载状态</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setLoading</span>(<span class="hljs-keyword">boolean</span> loading) {
        isLoading = loading;
        <span class="hljs-keyword">if</span> (isLoading) {
            mListView.addFooterView(mListViewFooter);
        } <span class="hljs-keyword">else</span> {
            mListView.removeFooterView(mListViewFooter);

        }
    }

    <span class="hljs-comment">// 设置监听器</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setOnLoadListener</span>(OnLoadListener loadListener) {
        mOnLoadListener = loadListener;
    }

    <span class="hljs-comment">// 加载更多的接口</span>
    <span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">interface</span> <span class="hljs-title">OnLoadListener</span> {</span>
        <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onLoad</span>();
    }
}

初始化数据都一样，不同的是记录了两个Y坐标，一个按下，一个抬起，用来判断滑动到底部时的上拉动作。<strong>getScaledTouchSlop</strong>是一个距离，表示滑动的时候，手的移动要大于这个距离才开始移动控件。如果小于这个距离就不触发移动控件，如viewpager就是用这个距离来判断用户是否翻页。
然后就是通过事件传递机制，拿到view的三个动作： 
<strong>MotionEvent.ACTION_DOWN</strong> 按下View，是所有事件的开始 
<strong>MotionEvent.ACTION_MOVE</strong> 滑动事件 
<strong>MotionEvent.ACTION_UP</strong> 与down对应，表示抬起 
当滑动的距离大于或者等于要求距离并且加载状态为false时，开始设置状态，加载数据，原理和上面一样。

接下里就是MainActivity的相关代码：

<span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MainActivity</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">Activity</span> <span class="hljs-keyword">implements</span> <span class="hljs-title">OnRefreshListener</span>,
        <span class="hljs-title">OnLoadListener</span> {</span>

    <span class="hljs-keyword">private</span> RefreshLayout swipeLayout;
    <span class="hljs-keyword">private</span> QQListView listView;
    <span class="hljs-keyword">private</span> MyAdapter adapter;
    <span class="hljs-keyword">private</span> List<Integer> list = <span class="hljs-keyword">new</span> ArrayList<Integer>();
    <span class="hljs-keyword">private</span> <span class="hljs-keyword">int</span> y = <span class="hljs-number">11</span>;

    <span class="hljs-annotation">@Override</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onCreate</span>(Bundle savedInstanceState) {

        <span class="hljs-keyword">super</span>.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        setData();
        setListener();
    }

    <span class="hljs-keyword">private</span> <span class="hljs-keyword">void</span> <span class="hljs-title">initView</span>() {
        swipeLayout = (RefreshLayout) findViewById(R.id.swipe_container);
        swipeLayout.setOnRefreshListener(<span class="hljs-keyword">this</span>);
        swipeLayout.setColorScheme(android.R.color.holo_blue_bright,
                android.R.color.holo_green_light,
                android.R.color.holo_orange_light,
                android.R.color.holo_red_light);

    }

    <span class="hljs-keyword">private</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setData</span>() {
        list = <span class="hljs-keyword">new</span> ArrayList<>();
        <span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">3</span>; i < <span class="hljs-number">12</span>; i++) {
            list.add(i);
        }

        listView = (QQListView) findViewById(R.id.list);
        adapter = <span class="hljs-keyword">new</span> MyAdapter(<span class="hljs-keyword">this</span>, list);
        listView.setAdapter(adapter);

        listView.setOnItemClickListener(<span class="hljs-keyword">new</span> OnItemClickListener() {

            <span class="hljs-annotation">@Override</span>
            <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onItemClick</span>(AdapterView<?> arg0, View arg1,
                    <span class="hljs-keyword">int</span> position, <span class="hljs-keyword">long</span> arg3) {

                Toast.makeText(getApplicationContext(),
                        <span class="hljs-string">"这是第"</span> + String.valueOf(position + <span class="hljs-number">1</span>) + <span class="hljs-string">"项"</span>,
                        Toast.LENGTH_SHORT).show();

            }
        });

        listView.setDelButtonClickListener(<span class="hljs-keyword">new</span> DelButtonClickListener() {

            <span class="hljs-annotation">@Override</span>
            <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">clickHappend</span>(<span class="hljs-keyword">int</span> position) {
                list.remove(position);
                refresh();
            }
        });

    }

    <span class="hljs-keyword">private</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setListener</span>() {
        swipeLayout.setOnRefreshListener(<span class="hljs-keyword">this</span>);
        swipeLayout.setOnLoadListener(<span class="hljs-keyword">this</span>);
    }

    <span class="hljs-annotation">@Override</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onRefresh</span>() {
        swipeLayout.postDelayed(<span class="hljs-keyword">new</span> Runnable() {

            <span class="hljs-annotation">@Override</span>
            <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">run</span>() {
                <span class="hljs-comment">// 更新数据</span>
                list.clear();
                y = <span class="hljs-number">12</span>;
                <span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i < <span class="hljs-number">13</span>; i++) {
                    list.add(i);
                }
                refresh();

                <span class="hljs-comment">// 更新完后调用该方法结束刷新</span>
                swipeLayout.setRefreshing(<span class="hljs-keyword">false</span>);
            }
        }, <span class="hljs-number">1000</span>);

    }

    <span class="hljs-annotation">@Override</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onLoad</span>() {
        swipeLayout.postDelayed(<span class="hljs-keyword">new</span> Runnable() {

            <span class="hljs-annotation">@Override</span>
            <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">run</span>() {
                <span class="hljs-comment">// 更新数据</span>
                y++;
                list.add(y);
                refresh();
                <span class="hljs-comment">// 更新完后调用该方法结束刷新</span>
                swipeLayout.setLoading(<span class="hljs-keyword">false</span>);
            }
        }, <span class="hljs-number">1000</span>);

    }

    <span class="hljs-keyword">private</span> <span class="hljs-keyword">void</span> <span class="hljs-title">refresh</span>() {
        adapter.setList(list);
        adapter.notifyDataSetChanged();
    }

}

实现自带的下拉刷新接口方法以及我们自己定义的上拉加载方法，然后在各自的方法里进行业务操作，我这里模拟的是简单数字刷新。到这里，SwipeRefreshLayout的下拉刷新与上拉加载已经完成。最后就是SwipeRefreshLayout的滑动删除。

这里的滑动删除参考的是鸿洋的这篇博客，代码注释，讲解都很详细:

http://blog.youkuaiyun.com/lmj623565791/article/details/22961279

滑动删除item原理就是通过回调拿到item的position，然后执行删除操作，更新适配器即可。难点就是解决上拉加载与下拉刷新操作与listview侧滑删除操作冲突的问题

<span class="hljs-annotation">@Override</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">dispatchTouchEvent</span>(MotionEvent ev) {

        <span class="hljs-comment">//获得动作类型</span>
        <span class="hljs-keyword">int</span> action = ev.getAction();
        <span class="hljs-keyword">int</span> x = (<span class="hljs-keyword">int</span>) ev.getX();
        <span class="hljs-keyword">int</span> y = (<span class="hljs-keyword">int</span>) ev.getY();
        <span class="hljs-keyword">switch</span> (action) {

        <span class="hljs-keyword">case</span> MotionEvent.ACTION_DOWN:
            xDown = x;
            yDown = y;
            <span class="hljs-javadoc">/**
             * 如果当前popupWindow显示，则直接隐藏，然后屏蔽ListView的touch事件的下传
             */</span>
            <span class="hljs-keyword">if</span> (mPopupWindow.isShowing()) {
                dismissPopWindow();
                <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;
            }
            <span class="hljs-comment">// 获得当前手指按下时的item的位置</span>
            mCurrentViewPos = pointToPosition(xDown, yDown);
            View view = getChildAt(mCurrentViewPos - getFirstVisiblePosition());
            mCurrentView = view;
            <span class="hljs-keyword">break</span>;
        <span class="hljs-keyword">case</span> MotionEvent.ACTION_MOVE:
            xMove = x;
            yMove = y;
            <span class="hljs-keyword">int</span> dx = xMove - xDown;
            <span class="hljs-keyword">int</span> dy = yMove - yDown;
            <span class="hljs-javadoc">/**
             * 判断是否是从右到左的滑动
             */</span>
            <span class="hljs-keyword">if</span> (xMove < xDown && Math.abs(dx) > touchSlop
                    && Math.abs(dy) < touchSlop) {
                <span class="hljs-comment">// Log.e(TAG, "touchslop = " + touchSlop + " , dx = " + dx +</span>
                <span class="hljs-comment">// " , dy = " + dy);</span>
                isSliding = <span class="hljs-keyword">true</span>;
            }
            <span class="hljs-keyword">break</span>;
        }
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">super</span>.dispatchTouchEvent(ev);
    }

    <span class="hljs-annotation">@Override</span>
    <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">onTouchEvent</span>(MotionEvent ev) {
        <span class="hljs-keyword">int</span> action = ev.getAction();
        <span class="hljs-javadoc">/**
         * 如果是从右到左的滑动才相应 
         */</span>
        <span class="hljs-keyword">if</span> (isSliding) {
            <span class="hljs-keyword">switch</span> (action) {
            <span class="hljs-keyword">case</span> MotionEvent.ACTION_MOVE:

                <span class="hljs-keyword">int</span>[] location = <span class="hljs-keyword">new</span> <span class="hljs-keyword">int</span>[<span class="hljs-number">2</span>];
                <span class="hljs-comment">// 获得当前item的位置x与y </span>
                mCurrentView.getLocationOnScreen(location);
                <span class="hljs-comment">// 设置popupWindow的动画  </span>
                mPopupWindow
                        .setAnimationStyle(R.style.popwindow_delete_btn_anim_style);
                mPopupWindow.update();
                mPopupWindow.showAtLocation(mCurrentView, Gravity.LEFT
                        | Gravity.TOP, location[<span class="hljs-number">0</span>] + mCurrentView.getWidth(),
                        location[<span class="hljs-number">1</span>] + mCurrentView.getHeight() / <span class="hljs-number">2</span>
                                - mPopupWindowHeight / <span class="hljs-number">2</span>);
                <span class="hljs-comment">// 设置删除按钮的回调  </span>
                mDelBtn.setOnClickListener(<span class="hljs-keyword">new</span> OnClickListener() {
                    <span class="hljs-annotation">@Override</span>
                    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onClick</span>(View v) {
                        <span class="hljs-keyword">if</span> (mListener != <span class="hljs-keyword">null</span>) {
                            mListener.clickHappend(mCurrentViewPos);
                            mPopupWindow.dismiss();
                        }
                    }
                });
                <span class="hljs-comment">// Log.e(TAG, "mPopupWindow.getHeight()=" + mPopupWindowHeight);</span>

                <span class="hljs-keyword">break</span>;
            <span class="hljs-keyword">case</span> MotionEvent.ACTION_UP:
                isSliding = <span class="hljs-keyword">false</span>;

            }
            <span class="hljs-comment">//  相应滑动期间屏幕itemClick事件，避免发生冲突</span>
            <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;
        }

        <span class="hljs-keyword">return</span> <span class="hljs-keyword">super</span>.onTouchEvent(ev);
    }

通过dispatchTouchEvent事件传递机制，设置当前是否响应用户滑动，然后在onTouchEvent中判断是否响应，如果响应则popupWindow以动画的形式展示出来。当然屏幕上如果存在PopupWindow，则屏幕ListView的滚动与Item的点击，以及从右到左滑动时屏幕Item的click事件都将被屏蔽。
其中关于dispatchTouchEvent，这里原理说的比较详细，就不班门弄斧了：