Android开发笔记-下拉刷新上拉加载控件，对所有View通用！

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 copy

package com.jingchen.pulltorefresh.pullableview;

public interface Pullable

{

/**

* 判断是否可以下拉，如果不需要下拉功能可以直接return false

*

* @return true如果可以下拉否则返回false

*/

boolean canPullDown();

/**

* 判断是否可以上拉，如果不需要上拉功能可以直接return false

*

* @return true如果可以上拉否则返回false

*/

boolean 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 copy

package com.jingchen.pulltorefresh;

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.ViewGroup;

import android.view.animation.AnimationUtils;

import android.view.animation.LinearInterpolator;

import android.view.animation.RotateAnimation;

import android.widget.RelativeLayout;

import android.widget.TextView;

import com.jingchen.pulltorefresh.pullableview.Pullable;

/**

* 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），

* 还有一个上拉头

*

* @author 陈靖

*/

public class PullToRefreshLayout extends RelativeLayout

{

public static final String TAG = "PullToRefreshLayout";

// 初始状态

public static final int INIT = 0;

// 释放刷新

public static final int RELEASE_TO_REFRESH = 1;

// 正在刷新

public static final int REFRESHING = 2;

// 释放加载

public static final int RELEASE_TO_LOAD = 3;

// 正在加载

public static final int LOADING = 4;

// 操作完毕

public static final int DONE = 5;

// 当前状态

private int state = INIT;

// 刷新回调接口

private OnRefreshListener mListener;

// 刷新成功

public static final int SUCCEED = 0;

// 刷新失败

public static final int FAIL = 1;

// 按下Y坐标，上一个事件点Y坐标

private float downY, lastY;

// 下拉的距离。注意：pullDownY和pullUpY不可能同时不为0

public float pullDownY = 0;

// 上拉的距离

private float pullUpY = 0;

// 释放刷新的距离

private float refreshDist = 200;

// 释放加载的距离

private float loadmoreDist = 200;

private MyTimer timer;

// 回滚速度

public float MOVE_SPEED = 8;

// 第一次执行布局

private boolean isLayout = false;

// 在刷新过程中滑动操作

private boolean isTouch = false;

// 手指滑动距离与下拉头的滑动距离比，中间会随正切函数变化

private float radio = 2;

// 下拉箭头的转180°动画

private RotateAnimation rotateAnimation;

// 均匀旋转动画

private RotateAnimation refreshingAnimation;

// 下拉头

private View refreshView;

// 下拉的箭头

private View pullView;

// 正在刷新的图标

private View refreshingView;

// 刷新结果图标

private View refreshStateImageView;

// 刷新结果：成功或失败

private TextView refreshStateTextView;

// 上拉头

private View loadmoreView;

// 上拉的箭头

private View pullUpView;

// 正在加载的图标

private View loadingView;

// 加载结果图标

private View loadStateImageView;

// 加载结果：成功或失败

private TextView loadStateTextView;

// 实现了Pullable接口的View

private View pullableView;

// 过滤多点触碰

private int mEvents;

// 这两个变量用来控制pull的方向，如果不加控制，当情况满足可上拉又可下拉时没法下拉

private boolean canPullDown = true;

private boolean canPullUp = true;

/**

* 执行自动回滚的handler

*/

Handler updateHandler = new Handler()

{

@Override

public void handleMessage(Message msg)

{

// 回弹速度随下拉距离moveDeltaY增大而增大

MOVE_SPEED = (float) (8 + 5 * Math.tan(Math.PI / 2

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

if (!isTouch)

{

// 正在刷新，且没有往上推的话则悬停，显示"正在刷新..."

if (state == REFRESHING && pullDownY <= refreshDist)

{

pullDownY = refreshDist;

timer.cancel();

} else if (state == LOADING && -pullUpY <= loadmoreDist)

{

pullUpY = -loadmoreDist;

timer.cancel();

}

}

if (pullDownY > 0)

pullDownY -= MOVE_SPEED;

else if (pullUpY < 0)

pullUpY += MOVE_SPEED;

if (pullDownY < 0)

{

// 已完成回弹

pullDownY = 0;

pullView.clearAnimation();

// 隐藏下拉头时有可能还在刷新，只有当前状态不是正在刷新时才改变状态

if (state != REFRESHING && state != LOADING)

changeState(INIT);

timer.cancel();

}

if (pullUpY > 0)

{

// 已完成回弹

pullUpY = 0;

pullUpView.clearAnimation();

// 隐藏下拉头时有可能还在刷新，只有当前状态不是正在刷新时才改变状态

if (state != REFRESHING && state != LOADING)

changeState(INIT);

timer.cancel();

}

// 刷新布局,会自动调用onLayout

requestLayout();

}

};

public void setOnRefreshListener(OnRefreshListener listener)

{

mListener = listener;

}

public PullToRefreshLayout(Context context)

{

super(context);

initView(context);

}

public PullToRefreshLayout(Context context, AttributeSet attrs)

{

super(context, attrs);

initView(context);

}

public PullToRefreshLayout(Context context, AttributeSet attrs, int defStyle)

{

super(context, attrs, defStyle);

initView(context);

}

private void initView(Context context)

{

timer = new MyTimer(updateHandler);

rotateAnimation = (RotateAnimation) AnimationUtils.loadAnimation(

context, R.anim.reverse_anim);

refreshingAnimation = (RotateAnimation) AnimationUtils.loadAnimation(

context, R.anim.rotating);

// 添加匀速转动动画

LinearInterpolator lir = new LinearInterpolator();

rotateAnimation.setInterpolator(lir);

refreshingAnimation.setInterpolator(lir);

}

private void hide()

{

timer.schedule(5);

}

/**

* 完成刷新操作，显示刷新结果。注意：刷新完成后一定要调用这个方法

*/

/**

* @param refreshResult

* PullToRefreshLayout.SUCCEED代表成功，PullToRefreshLayout.FAIL代表失败

*/

public void refreshFinish(int refreshResult)

{

refreshingView.clearAnimation();

refreshingView.setVisibility(View.GONE);

switch (refreshResult)

{

case SUCCEED:

// 刷新成功

refreshStateImageView.setVisibility(View.VISIBLE);

refreshStateTextView.setText(R.string.refresh_succeed);

refreshStateImageView

.setBackgroundResource(R.drawable.refresh_succeed);

break;

case FAIL:

default:

// 刷新失败

refreshStateImageView.setVisibility(View.VISIBLE);

refreshStateTextView.setText(R.string.refresh_fail);

refreshStateImageView

.setBackgroundResource(R.drawable.refresh_failed);

break;

}

// 刷新结果停留1秒

new Handler()

{

@Override

public void handleMessage(Message msg)

{

changeState(DONE);

hide();

}

}.sendEmptyMessageDelayed(0, 1000);

}

/**

* 加载完毕，显示加载结果。注意：加载完成后一定要调用这个方法

*

* @param refreshResult

* PullToRefreshLayout.SUCCEED代表成功，PullToRefreshLayout.FAIL代表失败

*/

public void loadmoreFinish(int refreshResult)

{

loadingView.clearAnimation();

loadingView.setVisibility(View.GONE);

switch (refreshResult)

{

case SUCCEED:

// 加载成功

loadStateImageView.setVisibility(View.VISIBLE);

loadStateTextView.setText(R.string.load_succeed);

loadStateImageView.setBackgroundResource(R.drawable.load_succeed);

break;

case FAIL:

default:

// 加载失败

loadStateImageView.setVisibility(View.VISIBLE);

loadStateTextView.setText(R.string.load_fail);

loadStateImageView.setBackgroundResource(R.drawable.load_failed);

break;

}

// 刷新结果停留1秒

new Handler()

{

@Override

public void handleMessage(Message msg)

{

changeState(DONE);

hide();

}

}.sendEmptyMessageDelayed(0, 1000);

}

private void changeState(int to)

{

state = to;

switch (state)

{

case INIT:

// 下拉布局初始状态

refreshStateImageView.setVisibility(View.GONE);

refreshStateTextView.setText(R.string.pull_to_refresh);

pullView.clearAnimation();

pullView.setVisibility(View.VISIBLE);

// 上拉布局初始状态

loadStateImageView.setVisibility(View.GONE);

loadStateTextView.setText(R.string.pullup_to_load);

pullUpView.clearAnimation();

pullUpView.setVisibility(View.VISIBLE);

break;

case RELEASE_TO_REFRESH:

// 释放刷新状态

refreshStateTextView.setText(R.string.release_to_refresh);

pullView.startAnimation(rotateAnimation);

break;

case REFRESHING:

// 正在刷新状态

pullView.clearAnimation();

refreshingView.setVisibility(View.VISIBLE);

pullView.setVisibility(View.INVISIBLE);

refreshingView.startAnimation(refreshingAnimation);

refreshStateTextView.setText(R.string.refreshing);

break;

case RELEASE_TO_LOAD:

// 释放加载状态

loadStateTextView.setText(R.string.release_to_load);

pullUpView.startAnimation(rotateAnimation);

break;

case LOADING:

// 正在加载状态

pullUpView.clearAnimation();

loadingView.setVisibility(View.VISIBLE);

pullUpView.setVisibility(View.INVISIBLE);

loadingView.startAnimation(refreshingAnimation);

loadStateTextView.setText(R.string.loading);

break;

case DONE:

// 刷新或加载完毕，啥都不做

break;

}

}

/**

* 不限制上拉或下拉

*/

private void releasePull()

{

canPullDown = true;

canPullUp = true;

}

/*

* （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;

timer.cancel();

mEvents = 0;

releasePull();

break;

case MotionEvent.ACTION_POINTER_DOWN:

case MotionEvent.ACTION_POINTER_UP:

// 过滤多点触碰

mEvents = -1;

break;

case MotionEvent.ACTION_MOVE:

if (mEvents == 0)

{

if (((Pullable) pullableView).canPullDown() && canPullDown

&& state != LOADING)

{

// 可以下拉，正在加载时不能下拉

// 对实际滑动距离做缩小，造成用力拉的感觉

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

if (pullDownY < 0)

{

pullDownY = 0;

canPullDown = false;

canPullUp = true;

}

if (pullDownY > getMeasuredHeight())

pullDownY = getMeasuredHeight();

if (state == REFRESHING)

{

// 正在刷新的时候触摸移动

isTouch = true;

}

} else if (((Pullable) pullableView).canPullUp() && canPullUp

&& state != REFRESHING)

{

// 可以上拉，正在刷新时不能上拉

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

if (pullUpY > 0)

{

pullUpY = 0;

canPullDown = true;

canPullUp = false;

}

if (pullUpY < -getMeasuredHeight())

pullUpY = -getMeasuredHeight();

if (state == LOADING)

{

// 正在加载的时候触摸移动

isTouch = true;

}

} else

releasePull();

} else

mEvents = 0;

lastY = ev.getY();

// 根据下拉距离改变比例

radio = (float) (2 + 2 * Math.tan(Math.PI / 2 / getMeasuredHeight()

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

requestLayout();

if (pullDownY <= refreshDist

<span style="white-space:pre"> </span>&& (state == RELEASE_TO_REFRESH || state == DONE)) {

<span style="white-space:pre"> </span>// 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 style="white-space:pre"> </span>changeState(INIT);

<span style="white-space:pre"> </span>}

<span style="white-space:pre"> </span>if (pullDownY >= refreshDist && (state == INIT || state == DONE)) {

<span style="white-space:pre"> </span>// 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 style="white-space:pre"> </span>changeState(RELEASE_TO_REFRESH);

<span style="white-space:pre"> </span>}

<span style="white-space:pre"> </span>// 下面是判断上拉加载的，同上，注意pullUpY是负值

<span style="white-space:pre"> </span>if (-pullUpY <= loadmoreDist

<span style="white-space:pre"> </span>&& (state == RELEASE_TO_LOAD || state == DONE)) {

<span style="white-space:pre"> </span>changeState(INIT);

<span style="white-space:pre"> </span>}

<span style="white-space:pre"> </span>if (-pullUpY >= loadmoreDist && (state == INIT || state == DONE)) {

<span style="white-space:pre"> </span>changeState(RELEASE_TO_LOAD);

<span style="white-space:pre"> </span>}

// 因为刷新和加载操作不能同时进行，所以pullDownY和pullUpY不会同时不为0，因此这里用(pullDownY +

// Math.abs(pullUpY))就可以不对当前状态作区分了

if ((pullDownY + Math.abs(pullUpY)) > 8)

{

// 防止下拉过程中误触发长按事件和点击事件

ev.setAction(MotionEvent.ACTION_CANCEL);

}

break;

case MotionEvent.ACTION_UP:

if (pullDownY > refreshDist || -pullUpY > loadmoreDist)

// 正在刷新时往下拉（正在加载时往上拉），释放后下拉头（上拉头）不隐藏

isTouch = false;

if (state == RELEASE_TO_REFRESH)

{

changeState(REFRESHING);

// 刷新操作

if (mListener != null)

mListener.onRefresh(this);

} else if (state == RELEASE_TO_LOAD)

{

changeState(LOADING);

// 加载操作

if (mListener != null)

mListener.onLoadMore(this);

}

hide();

default:

break;

}

// 事件分发交给父类

super.dispatchTouchEvent(ev);

return true;

}

private void initView()

{

// 初始化下拉布局

pullView = refreshView.findViewById(R.id.pull_icon);

refreshStateTextView = (TextView) refreshView

.findViewById(R.id.state_tv);

refreshingView = refreshView.findViewById(R.id.refreshing_icon);

refreshStateImageView = refreshView.findViewById(R.id.state_iv);

// 初始化上拉布局

pullUpView = loadmoreView.findViewById(R.id.pullup_icon);

loadStateTextView = (TextView) loadmoreView

.findViewById(R.id.loadstate_tv);

loadingView = loadmoreView.findViewById(R.id.loading_icon);

loadStateImageView = loadmoreView.findViewById(R.id.loadstate_iv);

}

@Override

protected void onLayout(boolean changed, int l, int t, int r, int b)

{

if (!isLayout)

{

// 这里是第一次进来的时候做一些初始化

refreshView = getChildAt(0);

pullableView = getChildAt(1);

loadmoreView = getChildAt(2);

isLayout = true;

initView();

refreshDist = ((ViewGroup) refreshView).getChildAt(0)

.getMeasuredHeight();

loadmoreDist = ((ViewGroup) loadmoreView).getChildAt(0)

.getMeasuredHeight();

}

// 改变子控件的布局，这里直接用(pullDownY + pullUpY)作为偏移量，这样就可以不对当前状态作区分

refreshView.layout(0,

(int) (pullDownY + pullUpY) - refreshView.getMeasuredHeight(),

refreshView.getMeasuredWidth(), (int) (pullDownY + pullUpY));

pullableView.layout(0, (int) (pullDownY + pullUpY),

pullableView.getMeasuredWidth(), (int) (pullDownY + pullUpY)

+ pullableView.getMeasuredHeight());

loadmoreView.layout(0,

(int) (pullDownY + pullUpY) + pullableView.getMeasuredHeight(),

loadmoreView.getMeasuredWidth(),

(int) (pullDownY + pullUpY) + pullableView.getMeasuredHeight()

+ loadmoreView.getMeasuredHeight());

}

class MyTimer

{

private Handler handler;

private Timer timer;

private MyTask mTask;

public MyTimer(Handler handler)

{

this.handler = handler;

timer = new Timer();

}

public void schedule(long period)

{

if (mTask != null)

{

mTask.cancel();

mTask = null;

}

mTask = new MyTask(handler);

timer.schedule(mTask, 0, period);

}

public void cancel()

{

if (mTask != null)

{

mTask.cancel();

mTask = null;

}

}

class MyTask extends TimerTask

{

private Handler handler;

public MyTask(Handler handler)

{

this.handler = handler;

}

@Override

public void run()

{

handler.obtainMessage().sendToTarget();

}

}

}

/**

* 刷新加载回调接口

*

* @author chenjing

*

*/

public interface OnRefreshListener

{

/**

* 刷新操作

*/

void onRefresh(PullToRefreshLayout pullToRefreshLayout);

/**

* 加载操作

*/

void 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 copy

package com.jingchen.pulltorefresh.pullableview;

import android.content.Context;

import android.util.AttributeSet;

import android.util.Log;

import android.widget.ListView;

public class PullableListView extends ListView implements Pullable

{

public PullableListView(Context context)

{

super(context);

}

public PullableListView(Context context, AttributeSet attrs)

{

super(context, attrs);

}

public PullableListView(Context context, AttributeSet attrs, int defStyle)

{

super(context, attrs, defStyle);

}

@Override

public boolean canPullDown()

{

if (getCount() == 0)

{

// 没有item的时候也可以下拉刷新

return true;

} else if (getFirstVisiblePosition() == 0

&& getChildAt(0).getTop() >= 0)

{

// 滑到ListView的顶部了

return true;

} else

return false;

}

@Override

public boolean canPullUp()

{

if (getCount() == 0)

{

// 没有item的时候也可以上拉加载

return true;

} else if (getLastVisiblePosition() == (getCount() - 1))

{

// 滑到底部了

if (getChildAt(getLastVisiblePosition() - getFirstVisiblePosition()) != null

&& getChildAt(

getLastVisiblePosition()

- getFirstVisiblePosition()).getBottom() <= getMeasuredHeight())

return true;

}

return false;

}

}

PullableExpandableListView：

[java] view
plain copy

package com.jingchen.pulltorefresh.pullableview;

import android.content.Context;

import android.util.AttributeSet;

import android.widget.ExpandableListView;

public class PullableExpandableListView extends ExpandableListView implements

Pullable

{

public PullableExpandableListView(Context context)

{

super(context);

}

public PullableExpandableListView(Context context, AttributeSet attrs)

{

super(context, attrs);

}

public PullableExpandableListView(Context context, AttributeSet attrs,

int defStyle)

{

super(context, attrs, defStyle);

}

@Override

public boolean canPullDown()

{

if (getCount() == 0)

{

// 没有item的时候也可以下拉刷新

return true;

} else if (getFirstVisiblePosition() == 0

&& getChildAt(0).getTop() >= 0)

{

// 滑到顶部了

return true;

} else

return false;

}

@Override

public boolean canPullUp()

{

if (getCount() == 0)

{

// 没有item的时候也可以上拉加载

return true;

} else if (getLastVisiblePosition() == (getCount() - 1))

{

// 滑到底部了

if (getChildAt(getLastVisiblePosition() - getFirstVisiblePosition()) != null

&& getChildAt(

getLastVisiblePosition()

- getFirstVisiblePosition()).getBottom() <= getMeasuredHeight())

return true;

}

return false;

}

}

PullableGridView：

[java] view
plain copy

package com.jingchen.pulltorefresh.pullableview;

import android.content.Context;

import android.util.AttributeSet;

import android.widget.GridView;

public class PullableGridView extends GridView implements Pullable

{

public PullableGridView(Context context)

{

super(context);

}

public PullableGridView(Context context, AttributeSet attrs)

{

super(context, attrs);

}

public PullableGridView(Context context, AttributeSet attrs, int defStyle)

{

super(context, attrs, defStyle);

}

@Override

public boolean canPullDown()

{

if (getCount() == 0)

{

// 没有item的时候也可以下拉刷新

return true;

} else if (getFirstVisiblePosition() == 0

&& getChildAt(0).getTop() >= 0)

{

// 滑到顶部了

return true;

} else

return false;

}

@Override

public boolean canPullUp()

{

if (getCount() == 0)

{

// 没有item的时候也可以上拉加载

return true;

} else if (getLastVisiblePosition() == (getCount() - 1))

{

// 滑到底部了

if (getChildAt(getLastVisiblePosition() - getFirstVisiblePosition()) != null

&& getChildAt(

getLastVisiblePosition()

- getFirstVisiblePosition()).getBottom() <= getMeasuredHeight())

return true;

}

return false;

}

}

PullableScrollView：

[java] view
plain copy

package com.jingchen.pulltorefresh.pullableview;

import android.content.Context;

import android.util.AttributeSet;

import android.widget.ScrollView;

public class PullableScrollView extends ScrollView implements Pullable

{

public PullableScrollView(Context context)

{

super(context);

}

public PullableScrollView(Context context, AttributeSet attrs)

{

super(context, attrs);

}

public PullableScrollView(Context context, AttributeSet attrs, int defStyle)

{

super(context, attrs, defStyle);

}

@Override

public boolean canPullDown()

{

if (getScrollY() == 0)

return true;

else

return false;

}

@Override

public boolean canPullUp()

{

if (getScrollY() >= (getChildAt(0).getHeight() - getMeasuredHeight()))

return true;

else

return false;

}

}

PullableWebView：

[java] view
plain copy

package com.jingchen.pulltorefresh.pullableview;

import android.content.Context;

import android.util.AttributeSet;

import android.webkit.WebView;

public class PullableWebView extends WebView implements Pullable

{

public PullableWebView(Context context)

{

super(context);

}

public PullableWebView(Context context, AttributeSet attrs)

{

super(context, attrs);

}

public PullableWebView(Context context, AttributeSet attrs, int defStyle)

{

super(context, attrs, defStyle);

}

@Override

public boolean canPullDown()

{

if (getScrollY() == 0)

return true;

else

return false;

}

@Override

public boolean canPullUp()

{

if (getScrollY() >= getContentHeight() * getScale()

- getMeasuredHeight())

return true;

else

return false;

}

}

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