Android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。

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：

 

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：

 

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0public 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Viewprivate 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(){@Overridepublic 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onLayoutrequestLayout();}};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(){@Overridepublic 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(){@Overridepublic 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) */@Overridepublic 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;}} elsereleasePull();} elsemEvents = 0;lastY = ev.getY();// 根据下拉距离改变比例radio = (float) (2 + 2 * Math.tan(Math.PI / 2 / getMeasuredHeight()* (pullDownY + Math.abs(pullUpY))));requestLayout();if (pullDownY <= refreshDist && state == RELEASE_TO_REFRESH){// 如果下拉距离没达到刷新的距离且当前状态是释放刷新，改变状态为下拉刷新changeState(INIT);}if (pullDownY >= refreshDist && state == INIT){// 如果下拉距离达到刷新的距离且当前状态是初始状态刷新，改变状态为释放刷新changeState(RELEASE_TO_REFRESH);}// 下面是判断上拉加载的，同上，注意pullUpY是负值if (-pullUpY <= loadmoreDist && state == RELEASE_TO_LOAD){changeState(INIT);}if (-pullUpY >= loadmoreDist && state == INIT){changeState(RELEASE_TO_LOAD);}// 因为刷新和加载操作不能同时进行，所以pullDownY和pullUpY不会同时不为0，因此这里用(pullDownY +// Math.abs(pullUpY))就可以不对当前状态作区分了if ((pullDownY + Math.abs(pullUpY)) > 8){// 防止下拉过程中误触发长按事件和点击事件ev.setAction(MotionEvent.ACTION_CANCEL);}break;case MotionEvent.ACTION_UP:if (pullDownY > refreshDist || -pullUpY > loadmoreDist)// 正在刷新时往下拉（正在加载时往上拉），释放后下拉头（上拉头）不隐藏isTouch = false;if (state == RELEASE_TO_REFRESH){changeState(REFRESHING);// 刷新操作if (mListener != null)mListener.onRefresh(this);} else if (state == RELEASE_TO_LOAD){changeState(LOADING);// 加载操作if (mListener != null)mListener.onLoadMore(this);}hide();default:break;}// 事件分发交给父类super.dispatchTouchEvent(ev);return true;}private void initView(){// 初始化下拉布局pullView = refreshView.findViewById(R.id.pull_icon);refreshStateTextView = (TextView) refreshView.findViewById(R.id.state_tv);refreshingView = refreshView.findViewById(R.id.refreshing_icon);refreshStateImageView = refreshView.findViewById(R.id.state_iv);// 初始化上拉布局pullUpView = loadmoreView.findViewById(R.id.pullup_icon);loadStateTextView = (TextView) loadmoreView.findViewById(R.id.loadstate_tv);loadingView = loadmoreView.findViewById(R.id.loading_icon);loadStateImageView = loadmoreView.findViewById(R.id.loadstate_iv);}@Overrideprotected 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;}@Overridepublic 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：

 

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);}@Overridepublic 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;} elsereturn false;}@Overridepublic 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：

 

package com.jingchen.pulltorefresh.pullableview;import android.content.Context;import android.util.AttributeSet;import android.widget.ExpandableListView;public class PullableExpandableListView extends ExpandableListView implementsPullable{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);}@Overridepublic 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;} elsereturn false;}@Overridepublic 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：

 

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);}@Overridepublic 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;} elsereturn false;}@Overridepublic 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：

 

 

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);}@Overridepublic boolean canPullDown(){if (getScrollY() == 0)return true;elsereturn false;}@Overridepublic boolean canPullUp(){if (getScrollY() >= (getChildAt(0).getHeight() - getMeasuredHeight()))return true;elsereturn false;}}

PullableWebView：

 

 

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);}@Overridepublic boolean canPullDown(){if (getScrollY() == 0)return true;elsereturn false;}@Overridepublic boolean canPullUp(){if (getScrollY() >= getContentHeight() * getScale()- getMeasuredHeight())return true;elsereturn 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。

demo下载链接：http://download.csdn.net/detail/u013334392/9621712