Android自定义控件实战——下拉刷新控件终结者：PullToRefreshLayout

 转载请声明出处http://blog.csdn.net/zhongkejingwang/article/details/38340701    

       说到下拉刷新控件，网上版本有很多，很多软件也都有下拉刷新功能。有一个叫XListView的，我看别人用过，没看过是咋实现的，看这名字估计是继承自ListView修改的，不过效果看起来挺丑的，也没什么扩展性，太单调了。看了QQ2014的列表下拉刷新，发现挺好看的，我喜欢，贴一下图看一下qq的下拉刷新效果：

                                          

    不错吧？嗯，是的。一看就知道实现方式不一样。咱们今天就来实现一个下拉刷新控件。由于有时候不仅仅是ListView需要下拉刷新，ExpandableListView和GridView也有这个需求，由于ListView，GridView都是AbsListView的子类，ExpandableListView是ListView的子类所以也是AbsListView的子类。所以我的思路是自定义一个对所有AbsListView的子类通用的下拉管理布局，叫PullToRefreshLayout，如果需要GridView，只需要在布局文件里将ListView换成GridView就行了，ExpandableListView也一样，不需要再继承什么GridView啊ListView啊乱七八糟的。

看上图，主要工作就是定义黑色大布局，红色部分是不下拉的时候的可见部分，可以是任意的AbsListView的子类（GridView，ListView，ExpandableListView等等）。其实我已经写好了，先看一下效果图：

正常拉法：

                          

强迫症拉法：

                 

上面是ListView的，下面是GridView的

                  

再来看一下ExpandableListView的下拉刷新效果：

                              

可以看到，点击事件和长按事件都能正常触发而不会误触发，在使用ExpandableListView的时候需要注意禁止展开时自动滚动，否则会出现bug。后面会提供demo源码下载，可以根据自己的需求去修改。

下面讲解PullToRefreshLayout的实现，在贴完整的源码之前先理解整个类的大概思路：

public class PullToRefreshLayout extends RelativeLayout implements OnTouchListener
{

    // 下拉的距离
    public float moveDeltaY = 0;
    // 是否可以下拉
    private boolean canPull = true;


    private void hideHead()
    {
        // 在这里开始异步隐藏下拉头，在松手的时候或这刷新完毕的时候隐藏
    }


    public void refreshFinish(int refreshResult)
    {
        // 完成刷新操作，显示刷新结果
    }

    private void changeState(int to)
    {
        // 改变当前所处的状态，有四个状态：下拉刷新、释放刷新、正在刷新、刷新完成
    }

    /*
     * （非 Javadoc）由父控件决定是否分发事件，防止事件冲突
     *
     * @see android.view.ViewGroup#dispatchTouchEvent(android.view.MotionEvent)
     */
    @Override
    public boolean dispatchTouchEvent(MotionEvent ev)
    {
        switch (ev.getActionMasked())
        {
        case MotionEvent.ACTION_DOWN:
            /*手指按下的时候，无法判断是否将要下拉，所以这时候break让父类把down事件分发给子View
            记录按下的坐标*/
            break;
        case MotionEvent.ACTION_MOVE:
            /*如果往上滑动且moveDetaY==0则说明不在下拉，break继续将move事件分发给子View
            如果往下拉，则计算下拉的距离moveDeltaY，根据moveDeltaY重新Layout子控件。但是
            由于down事件传到了子View，如果不清除子View的事件，会导致子View误触发长按事件和点击事件。所以在这里清除子View的事件回调。
            下拉超过一定的距离时，改变当前状态*/
            break;
        case MotionEvent.ACTION_UP:
            //根据当前状态执行刷新操作或者hideHead
        default:
            break;
        }
        // 事件分发交给父类
        return super.dispatchTouchEvent(ev);
    }



    /*
     * （非 Javadoc）绘制阴影效果，颜色值可以修改
     *
     * @see android.view.ViewGroup#dispatchDraw(android.graphics.Canvas)
     */
    @Override
    protected void dispatchDraw(Canvas canvas)
    {
        //在这里用一个渐变绘制分界线阴影
    }



    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b)
    {
        //这个方法就是重新Layout子View了，根据moveDeltaY来定位子View的位置
    }


    @Override
    public boolean onTouch(View v, MotionEvent event)
    {
        //这个是OnTouchListener的方法，只判断AbsListView的状态来决定是否canPull，除此之外不做其他处理
    }
}

可以看到，这里复写了ViewGroup的dispatchTouchEvent，这样就可以掌控事件的分发，如果不了解这个方法可以看一下这篇Android事件分发、View事件Listener全解析。之所以要控制事件分发是因为我们不可能知道手指down在AbsListView上之后将往上滑还是往下拉，所以down事件会分发给AbsListView的，但是在move的时候就需要看情况了，因为我们不想在下拉的同时AbsListView也在滑动，所以在下拉的时候不分发move事件，但这样问题又来了，前面AbsListView已经接收了down事件，如果这时候不分发move事件给它，它会触发长按事件或者点击事件，所以在这里还需要清除AbsListView消息列表中的callback。

onLayout用于重新布置下拉头和AbsListView的位置的，这个不难理解。

理解了大概思路之后，看一下PullToRefreshLayout完整的源码吧~

package com.jingchen.pulltorefresh;

import java.lang.reflect.Field;
import java.util.Timer;
import java.util.TimerTask;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.RectF;
import android.graphics.Shader.TileMode;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.view.animation.LinearInterpolator;
import android.view.animation.RotateAnimation;
import android.widget.AbsListView;
import android.widget.RelativeLayout;
import android.widget.TextView;

/**
 * 整个下拉刷新就这一个布局，用来管理两个子控件，其中一个是下拉头，另一个是包含内容的contentView（可以是AbsListView的任何子类）
 *
 * @author 陈靖
 */
public class PullToRefreshLayout extends RelativeLayout implements OnTouchListener
{
    public static final String TAG = "PullToRefreshLayout";
    // 下拉刷新
    public static final int PULL_TO_REFRESH = 0;
    // 释放刷新
    public static final int RELEASE_TO_REFRESH = 1;
    // 正在刷新
    public static final int REFRESHING = 2;
    // 刷新完毕
    public static final int DONE = 3;
    // 当前状态
    private int state = PULL_TO_REFRESH;
    // 刷新回调接口
    private OnRefreshListener mListener;
    // 刷新成功
    public static final int REFRESH_SUCCEED = 0;
    // 刷新失败
    public static final int REFRESH_FAIL = 1;
    // 下拉头
    private View headView;
    // 内容
    private View contentView;
    // 按下Y坐标，上一个事件点Y坐标
    private float downY, lastY;
    // 下拉的距离
    public float moveDeltaY = 0;
    // 释放刷新的距离
    private float refreshDist = 200;
    private Timer timer;
    private MyTimerTask mTask;
    // 回滚速度
    public float MOVE_SPEED = 8;
    // 第一次执行布局
    private boolean isLayout = false;
    // 是否可以下拉
    private boolean canPull = true;
    // 在刷新过程中滑动操作
    private boolean isTouchInRefreshing = 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;
    // 下拉的箭头
    private View pullView;
    // 正在刷新的图标
    private View refreshingView;
    // 刷新结果图标
    private View stateImageView;
    // 刷新结果：成功或失败
    private TextView stateTextView;
    /**
     * 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() * moveDeltaY));
            if (state == REFRESHING && moveDeltaY <= refreshDist && !isTouchInRefreshing)
            {
                // 正在刷新，且没有往上推的话则悬停，显示"正在刷新..."
                moveDeltaY = refreshDist;
                mTask.cancel();
            }
            if (canPull)
                moveDeltaY -= MOVE_SPEED;
            if (moveDeltaY <= 0)
            {
                // 已完成回弹
                moveDeltaY = 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)
                    changeState(PULL_TO_REFRESH);
                mTask.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 Timer();
        mTask = new MyTimerTask(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 hideHead()
    {
        if (mTask != null)
        {
            mTask.cancel();
            mTask = null;
        }
        mTask = new MyTimerTask(updateHandler);
        timer.schedule(mTask, 0, 5);
    }

    /**
     * 完成刷新操作，显示刷新结果
     */
    public void refreshFinish(int refreshResult)
    {
        refreshingView.clearAnimation();
        refreshingView.setVisibility(View.GONE);
        switch (refreshResult)
        {
        case REFRESH_SUCCEED:
            // 刷新成功
            stateImageView.setVisibility(View.VISIBLE);
            stateTextView.setText(R.string.refresh_succeed);
            stateImageView.setBackgroundResource(R.drawable.refresh_succeed);
            break;
        case REFRESH_FAIL:
            // 刷新失败
            stateImageView.setVisibility(View.VISIBLE);
            stateTextView.setText(R.string.refresh_fail);
            stateImageView.setBackgroundResource(R.drawable.refresh_failed);
            break;
        default:
            break;
        }
        // 刷新结果停留1秒
        new Handler()
        {
            @Override
            public void handleMessage(Message msg)
            {
                state = PULL_TO_REFRESH;
                hideHead();
            }
        }.sendEmptyMessageDelayed(0, 1000);
    }

    private void changeState(int to)
    {
        state = to;
        switch (state)
        {
        case PULL_TO_REFRESH:
            // 下拉刷新
            stateImageView.setVisibility(View.GONE);
            stateTextView.setText(R.string.pull_to_refresh);
            pullView.clearAnimation();
            pullView.setVisibility(View.VISIBLE);
            break;
        case RELEASE_TO_REFRESH:
            // 释放刷新
            stateTextView.setText(R.string.release_to_refresh);
            pullView.startAnimation(rotateAnimation);
            break;
        case REFRESHING:
            // 正在刷新
            pullView.clearAnimation();
            refreshingView.setVisibility(View.VISIBLE);
            pullView.setVisibility(View.INVISIBLE);
            refreshingView.startAnimation(refreshingAnimation);
            stateTextView.setText(R.string.refreshing);
            break;
        default:
            break;
        }
    }

    /*
     * （非 Javadoc）由父控件决定是否分发事件，防止事件冲突
     *
     * @see android.view.ViewGroup#dispatchTouchEvent(android.view.MotionEvent)
     */
    @Override
    public boolean dispatchTouchEvent(MotionEvent ev)
    {
        switch (ev.getActionMasked())
        {
        case MotionEvent.ACTION_DOWN:
            downY = ev.getY();
            lastY = downY;
            if (mTask != null)
            {
                mTask.cancel();
            }
            /*
             * 触碰的地方位于下拉头布局，由于我们没有对下拉头做事件响应，这时候它会给咱返回一个false导致接下来的事件不再分发进来。
             * 所以我们不能交给父类分发，直接返回true
             */
            if (ev.getY() < moveDeltaY)
                return true;
            break;
        case MotionEvent.ACTION_MOVE:
            // canPull这个值在底下onTouch中会根据ListView是否滑到顶部来改变，意思是是否可下拉
            if (canPull)
            {
                // 对实际滑动距离做缩小，造成用力拉的感觉
                moveDeltaY = moveDeltaY + (ev.getY() - lastY) / radio;
                if (moveDeltaY < 0)
                    moveDeltaY = 0;
                if (moveDeltaY > getMeasuredHeight())
                    moveDeltaY = getMeasuredHeight();
                if (state == REFRESHING)
                {
                    // 正在刷新的时候触摸移动
                    isTouchInRefreshing = true;
                }
            }
            lastY = ev.getY();
            // 根据下拉距离改变比例
            radio = (float) (2 + 2 * Math.tan(Math.PI / 2 / getMeasuredHeight() * moveDeltaY));
            requestLayout();
            if (moveDeltaY <= 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(PULL_TO_REFRESH);
            }
            if (moveDeltaY >= refreshDist && state == PULL_TO_REFRESH)
            {
                changeState(RELEASE_TO_REFRESH);
            }
            if (moveDeltaY > 8)
            {
                // 防止下拉过程中误触发长按事件和点击事件
                clearContentViewEvents();
            }
            if (moveDeltaY > 0)
            {
                // 正在下拉，不让子控件捕获事件
                return true;
            }
            break;
        case MotionEvent.ACTION_UP:
            if (moveDeltaY > refreshDist)
                // 正在刷新时往下拉释放后下拉头不隐藏
                isTouchInRefreshing = false;
            if (state == RELEASE_TO_REFRESH)
            {
                changeState(REFRESHING);
                // 刷新操作
                if (mListener != null)
                    mListener.onRefresh();
            } else
            {

            }
            hideHead();
        default:
            break;
        }
        // 事件分发交给父类
        return super.dispatchTouchEvent(ev);
    }

    /**
     * 通过反射修改字段去掉长按事件和点击事件
     */
    private void clearContentViewEvents()
    {
        try
        {
            Field[] fields = AbsListView.class.getDeclaredFields();
            for (int i = 0; i < fields.length; i++)
                if (fields[i].getName().equals("mPendingCheckForLongPress"))
                {
                    // mPendingCheckForLongPress是AbsListView中的字段，通过反射获取并从消息列表删除，去掉长按事件
                    fields[i].setAccessible(true);
                    contentView.getHandler().removeCallbacks((Runnable) fields[i].get(contentView));
                } else if (fields[i].getName().equals("mTouchMode"))
                {
                    // TOUCH_MODE_REST = -1， 这个可以去除点击事件
                    fields[i].setAccessible(true);
                    fields[i].set(contentView, -1);
                }
            // 去掉焦点
            ((AbsListView) contentView).getSelector().setState(new int[]
            { 0 });
        } catch (Exception e)
        {
            Log.d(TAG, "error : " + e.toString());
        }
    }

    /*
     * （非 Javadoc）绘制阴影效果，颜色值可以修改
     *
     * @see android.view.ViewGroup#dispatchDraw(android.graphics.Canvas)
     */
    @Override
    protected void dispatchDraw(Canvas canvas)
    {
        super.dispatchDraw(canvas);
        if (moveDeltaY == 0)
            return;
        RectF rectF = new RectF(0, 0, getMeasuredWidth(), moveDeltaY);
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        // 阴影的高度为26
        LinearGradient linearGradient = new LinearGradient(0, moveDeltaY, 0, moveDeltaY - 26, 0x66000000, 0x00000000, TileMode.CLAMP);
        paint.setShader(linearGradient);
        paint.setStyle(Style.FILL);
        // 在moveDeltaY处往上变淡
        canvas.drawRect(rectF, paint);
    }

    private void initView()
    {
        pullView = headView.findViewById(R.id.pull_icon);
        stateTextView = (TextView) headView.findViewById(R.id.state_tv);
        refreshingView = headView.findViewById(R.id.refreshing_icon);
        stateImageView = headView.findViewById(R.id.state_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
            headView = getChildAt(0);
            contentView = getChildAt(1);
            // 给AbsListView设置OnTouchListener
            contentView.setOnTouchListener(this);
            isLayout = true;
            initView();
            refreshDist = ((ViewGroup) headView).getChildAt(0).getMeasuredHeight();
        }
        if (canPull)
        {
            // 改变子控件的布局
            headView.layout(0, (int) moveDeltaY - headView.getMeasuredHeight(), headView.getMeasuredWidth(), (int) moveDeltaY);
            contentView.layout(0, (int) moveDeltaY, contentView.getMeasuredWidth(), (int) moveDeltaY + contentView.getMeasuredHeight());
        }else super.onLayout(changed, l, t, r, b);
    }

    class MyTimerTask extends TimerTask
    {
        Handler handler;

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

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

    }

    @Override
    public boolean onTouch(View v, MotionEvent event)
    {
        // 第一个item可见且滑动到顶部
        AbsListView alv = null;
        try
        {
            alv = (AbsListView) v;
        } catch (Exception e)
        {
            Log.d(TAG, e.getMessage());
            return false;
        }
        if (alv.getCount() == 0)
        {
            // 没有item的时候也可以下拉刷新
            canPull = true;
        } else if (alv.getFirstVisiblePosition() == 0 && alv.getChildAt(0).getTop() >= 0)
        {
            // 滑到AbsListView的顶部了
            canPull = true;
        } else
            canPull = false;
        return false;
    }
}

代码中的注释已经写的很清楚了。

既然PullToRefreshLayout已经写好了，接下来就来使用这个Layout实现下拉刷新~

首先得写个OnRefreshListener接口来回调刷新操作：

public interface OnRefreshListener {
    void onRefresh();
}

就一个刷新操作的方法，待会儿让Activity实现这个接口就可以在Activity中执行刷新操作了。

看一下MainActivity的布局：

<com.jingchen.pulltorefresh.PullToRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/refresh_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <include layout="@layout/refresh_head" />


    <ListView
        android:id="@+id/content_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white"
        android:divider="@color/gray"
        android:dividerHeight="1dp" >
    ListView>

com.jingchen.pulltorefresh.PullToRefreshLayout>

PullToRefreshLayout只能包含两个子控件：refresh_head和content_view。

看一下refresh_head的布局：

xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/head_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/light_blue" >

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:paddingBottom="20dp"
        android:paddingTop="20dp" >

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true" >

            <ImageView
                android:id="@+id/pull_icon"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginLeft="60dp"
                android:background="@drawable/pull_icon_big" />

            <ImageView
                android:id="@+id/refreshing_icon"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginLeft="60dp"
                android:background="@drawable/refreshing"
                android:visibility="gone" />

            <TextView
                android:id="@+id/state_tv"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:text="@string/pull_to_refresh"
                android:textColor="@color/white"
                android:textSize="16sp" />

            <ImageView
                android:id="@+id/state_iv"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginRight="8dp"
                android:layout_toLeftOf="@id/state_tv"
                android:visibility="gone" />
        RelativeLayout>
    RelativeLayout>

RelativeLayout>

可以根据需要修改refresh_head的布局然后在PullToRefreshLayout中处理，但是相关View的id要和PullToRefreshLayout中用到的保持同步！

接下来是MainActivity的代码：

package com.jingchen.pulltorefresh;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.view.animation.LinearInterpolator;
import android.view.animation.RotateAnimation;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.ExpandableListView.OnGroupClickListener;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

/**
 * 除了下拉刷新，在contenview为ListView的情况下我给ListView增加了FooterView，实现点击加载更多
 *
 * @author 陈靖
 *
 */
public class MainActivity extends Activity implements OnRefreshListener, OnClickListener
{
    private AbsListView alv;
    private PullToRefreshLayout refreshLayout;
    private View loading;
    private RotateAnimation loadingAnimation;
    private TextView loadTextView;
    private MyAdapter adapter;
    private boolean isLoading = false;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
    }

    private void init()
    {
        alv = (AbsListView) findViewById(R.id.content_view);
        refreshLayout = (PullToRefreshLayout) findViewById(R.id.refresh_view);
        refreshLayout.setOnRefreshListener(this);
        initListView();

        loadingAnimation = (RotateAnimation) AnimationUtils.loadAnimation(this, R.anim.rotating);
        // 添加匀速转动动画
        LinearInterpolator lir = new LinearInterpolator();
        loadingAnimation.setInterpolator(lir);
    }

    /**
     * ListView初始化方法
     */
    private void initListView()
    {
        List items = new ArrayList();
        for (int i = 0; i < 30; i++)
        {
            items.add("这里是item " + i);
        }
        // 添加head
        View headView = getLayoutInflater().inflate(R.layout.listview_head, null);
        ((ListView) alv).addHeaderView(headView, null, false);
        // 添加footer
        View footerView = getLayoutInflater().inflate(R.layout.load_more, null);
        loading = footerView.findViewById(R.id.loading_icon);
        loadTextView = (TextView) footerView.findViewById(R.id.loadmore_tv);
        ((ListView) alv).addFooterView(footerView, null, false);
        footerView.setOnClickListener(this);
        adapter = new MyAdapter(this, items);
        alv.setAdapter(adapter);
        alv.setOnItemLongClickListener(new OnItemLongClickListener()
        {

            @Override
            public boolean onItemLongClick(AdapterView parent, View view, int position, long id)
            {
                Toast.makeText(MainActivity.this, "LongClick on " + parent.getAdapter().getItemId(position), Toast.LENGTH_SHORT).show();
                return true;
            }
        });
        alv.setOnItemClickListener(new OnItemClickListener()
        {

            @Override
            public void onItemClick(AdapterView parent, View view, int position, long id)
            {
                Toast.makeText(MainActivity.this, " Click on " + parent.getAdapter().getItemId(position), Toast.LENGTH_SHORT).show();
            }
        });
    }

    /**
     * GridView初始化方法
     */
    private void initGridView()
    {
        List items = new ArrayList();
        for (int i = 0; i < 30; i++)
        {
            items.add("这里是item " + i);
        }
        adapter = new MyAdapter(this, items);
        alv.setAdapter(adapter);
        alv.setOnItemLongClickListener(new OnItemLongClickListener()
        {

            @Override
            public boolean onItemLongClick(AdapterView parent, View view, int position, long id)
            {
                Toast.makeText(MainActivity.this, "LongClick on " + parent.getAdapter().getItemId(position), Toast.LENGTH_SHORT).show();
                return true;
            }
        });
        alv.setOnItemClickListener(new OnItemClickListener()
        {

            @Override
            public void onItemClick(AdapterView parent, View view, int position, long id)
            {
                Toast.makeText(MainActivity.this, " Click on " + parent.getAdapter().getItemId(position), Toast.LENGTH_SHORT).show();
            }
        });
    }

    /**
     * ExpandableListView初始化方法
     */
    private void initExpandableListView()
    {
        ((ExpandableListView) alv).setAdapter(new ExpandableListAdapter(this));
        ((ExpandableListView) alv).setOnChildClickListener(new OnChildClickListener()
        {

            @Override
            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id)
            {
                Toast.makeText(MainActivity.this, " Click on group " + groupPosition + " item " + childPosition, Toast.LENGTH_SHORT).show();
                return true;
            }
        });
        ((ExpandableListView) alv).setOnItemLongClickListener(new OnItemLongClickListener()
        {

            @Override
            public boolean onItemLongClick(AdapterView parent, View view, int position, long id)
            {
                Toast.makeText(MainActivity.this, "LongClick on " + parent.getAdapter().getItemId(position), Toast.LENGTH_SHORT).show();
                return true;
            }
        });
        ((ExpandableListView) alv).setOnGroupClickListener(new OnGroupClickListener()
        {

            @Override
            public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id)
            {
                if (parent.isGroupExpanded(groupPosition))
                {
                    // 如果展开则关闭
                    parent.collapseGroup(groupPosition);
                } else
                {
                    // 如果关闭则打开，注意这里是手动打开不要默认滚动否则会有bug
                    parent.expandGroup(groupPosition);
                }
                return true;
            }
        });
    }

    @Override
    public void onRefresh()
    {
        // 下拉刷新操作
        new Handler()
        {
            @Override
            public void handleMessage(Message msg)
            {
                refreshLayout.refreshFinish(PullToRefreshLayout.REFRESH_SUCCEED);
            }
        }.sendEmptyMessageDelayed(0, 5000);
    }

    @Override
    public void onClick(View v)
    {
        switch (v.getId())
        {
        case R.id.loadmore_layout:
            if (!isLoading)
            {
                loading.setVisibility(View.VISIBLE);
                loading.startAnimation(loadingAnimation);
                loadTextView.setText(R.string.loading);
                isLoading = true;
            }
            break;
        default:
            break;
        }

    }

    class ExpandableListAdapter extends BaseExpandableListAdapter
    {
        private String[] groupsStrings;// = new String[] { "这里是group 0",
                                        // "这里是group 1", "这里是group 2" };
        private String[][] groupItems;
        private Context context;

        public ExpandableListAdapter(Context context)
        {
            this.context = context;
            groupsStrings = new String[8];
            for (int i = 0; i < groupsStrings.length; i++)
            {
                groupsStrings[i] = new String("这里是group " + i);
            }
            groupItems = new String[8][8];
            for (int i = 0; i < groupItems.length; i++)
                for (int j = 0; j < groupItems[i].length; j++)
                {
                    groupItems[i][j] = new String("这里是group " + i + "里的item " + j);
                }
        }

        @Override
        public int getGroupCount()
        {
            return groupsStrings.length;
        }

        @Override
        public int getChildrenCount(int groupPosition)
        {
            return groupItems[groupPosition].length;
        }

        @Override
        public Object getGroup(int groupPosition)
        {
            return groupsStrings[groupPosition];
        }

        @Override
        public Object getChild(int groupPosition, int childPosition)
        {
            return groupItems[groupPosition][childPosition];
        }

        @Override
        public long getGroupId(int groupPosition)
        {
            return groupPosition;
        }

        @Override
        public long getChildId(int groupPosition, int childPosition)
        {
            return childPosition;
        }

        @Override
        public boolean hasStableIds()
        {
            return true;
        }

        @Override
        public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent)
        {
            View view = LayoutInflater.from(context).inflate(R.layout.list_item_layout, null);
            TextView tv = (TextView) view.findViewById(R.id.name_tv);
            tv.setText(groupsStrings[groupPosition]);
            return view;
        }

        @Override
        public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent)
        {
            View view = LayoutInflater.from(context).inflate(R.layout.list_item_layout, null);
            TextView tv = (TextView) view.findViewById(R.id.name_tv);
            tv.setText(groupItems[groupPosition][childPosition]);
            return view;
        }

        @Override
        public boolean isChildSelectable(int groupPosition, int childPosition)
        {
            return true;
        }

    }

}

在MainActivity中判断contentView是ListView的话给ListView添加了FooterView实现点击加载更多的功能。这只是一个演示PullToRefreshLayout使用的demo，可以参照一下修改。我已经在里面写了ListView，GridView和ExpandableListView的初始化方法，根据自己使用的是哪个来调用吧。那么这是ListView的下拉刷新和加载更多。如果我要GridView也有下拉刷新功能呢？那就把MainActivity的布局换成这样：

<com.jingchen.pulltorefresh.PullToRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/refresh_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <include layout="@layout/refresh_head" />

    <GridView
        android:id="@+id/content_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white"
        android:columnWidth="90dp"
        android:gravity="center"
        android:horizontalSpacing="10dp"
        android:numColumns="auto_fit"
        android:stretchMode="columnWidth"
        android:verticalSpacing="15dp" >
    GridView>

com.jingchen.pulltorefresh.PullToRefreshLayout>

如果是ExpandableListView则把布局改成这样：

<com.jingchen.pulltorefresh.PullToRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/refresh_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <include layout="@layout/refresh_head" />

    <ExpandableListView
        android:id="@+id/content_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white" >
    ExpandableListView>

com.jingchen.pulltorefresh.PullToRefreshLayout>

怎么样？很简单吧？简单易用，不用再去继承修改了~

点击下载源码