首先给大家展示下效果图，感觉还不错，请继续往下阅读：
下拉刷新：
上划加载
在项目更新的过程中，遇到了一个将XListView换成recyclerView的需求，而且更换完之后大体效果不能变，但是对于下拉刷新这样的效果，谷歌给出的解决方案是把RecyclerView放在一个SwipeRefreshLayout中，但是这样其实是拉下一个小圆形控件实现的，和XListView的header效果不同。在网上找了很多的别人代码，都没有实现我想要的效果，于是自己动手写了一个。
具体实现的效果有以下几条
下拉刷新功能：
1、实现一个有弹性的拖出效果：思路参考XListView，recyclerView的position=0的位置放一个header布局，这个布局的margin top默认为负的布局高度，所以这块布局就一直处于屏幕外部，在下拉的时候通过onTouchListener根据手指的移动动态修改margin top，慢慢的拖出，当拖出的距离也就是margin top变为正数以后，就盖面header布局的状态，改变箭头的方向并改变提示语
2、实现有弹性的回弹效果：用timerTask写了一个动态修改的header布局的margin top的动画，每隔一定的时间减小margin top的值，当用户松手的时候通过一个函数updateHeaderHeight（）来执行这个动画。
3、实现用户非手动拖拉的自动刷新效果：这个recyclerView还有一个方法叫forceRefresh（），就是不需要用户手动下拉，头部自己滚动出来，然后刷新完再自己收回去，自动下拉也是用一个timerTask每隔十几毫秒增加margin top的值让头部慢慢露出来
上划加载更多功能：
1、实现滚动到底部自动停住效果： 有时候recyclerVIew滚动太快，滚到底部的时候会根据惯性向上飘，这个地方到底的时候监控recyclerView滚动速度，如果非常快说明是惯性滚动，就不修改footer布局的高度
2、实现向上拖动效果：复写了recyclerView的onScrollListener，在手指向上滚动的时候，通过updateFooterHeight（）方法动态修改底部footerView的margin bottom，同headerView一样，在手指移动的时候让这个margin跟着变大，以增加footer布局的高度，而且手指移动的越网上，增加的margin的高度就越小，实现一个有弹性的上拉效果，防止误操作。
3、实现自动回弹的效果：通过监控footer布局的margin bottom来确定松手的时候是否需要开始刷新，如果margin bottom大于某个值得时候就修改footer布局的状态从normal变成ready，在ready状态下松手就开始刷新操作，回弹也像header布局一样通过一个timerTask每隔十几毫秒修改margin的大小来实现回弹效果
注意事项：
1、为了实现头部和底部的代码分离，头部用的是onTouchListener，底部用的是onScrollListener
2、本recyclerVIew里面已经内置了一个layoutManager,所以不要给recyclerView再设置layoutManager,否则会出现头部不出来，下拉报空指针的情况，底部出现但是滑动没有效果
3、这个recyclerView内置了一个抽象类作为adapter，请继承这个内置的AlxDragRecyclerViewAdapter使用，或者按照这里面的逻辑重新写adapter
有其他的问题欢迎问我
4、一些常用的功能，比如设置该控件是否能够支持下拉加载和上拉刷新，等等api接口，请直接参考XListView的用法即可
使用方法：
继承AlxDragRecyclerViewAdapter写一个adapter，然后写两个类分别实现OnRefreshListener和LoadMoreListener，把具体的刷新逻辑写在里面，在准备好显示数据后调用adapter的notifyDataSetChanged（）方法或notifyItemInserted（）方法，并执行该recyclerView的stopLoadmore（）方法和stopRefresh（）方法。
下面是代码，这个控件有很多的内部类，包括头部，底部的布局控件（CustomDragHeaderView，CustomDragFooterView），adapter，layoutmanager都已经以内部类的方式集成在里面，减少迁移时候的复杂度
import android.content.Context; import android.graphics.Color; import android.os.Handler; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.util.AttributeSet; import android.util.Log; import android.view.LayoutInflater; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.view.WindowManager; import android.view.animation.Animation; import android.view.animation.RotateAnimation; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.TextView; import com.xxx.app.R; import java.util.List; import java.util.Timer; import java.util.TimerTask; /** * Created by Alex on 2016/1/27. */ public class AlxRefreshLoadMoreRecyclerView extends RecyclerView { private int footerHeight = -1; LinearLayoutManager layoutManager; // -- footer view private CustomDragRecyclerFooterView mFooterView; private boolean mEnablePullLoad; private boolean mPullLoading; private boolean isBottom; private boolean mIsFooterReady = false; private LoadMoreListener loadMoreListener; // -- header view private CustomDragHeaderView mHeaderView; private boolean mEnablePullRefresh = true; private boolean mIsRefreshing; private boolean isHeader; private boolean mIsHeaderReady = false; private Timer timer; private float oldY; Handler handler = new Handler(); private OnRefreshListener refreshListener; private AlxDragRecyclerViewAdapter adapter; private int maxPullHeight = 50;//最多下拉高度的px值 private static final int HEADER_HEIGHT = 68;//头部高度68dp private static final int MAX_PULL_LENGTH = 150;//最多下拉150dp private OnClickListener footerClickListener; public AlxRefreshLoadMoreRecyclerView(Context context) { super(context); initView(context); } public AlxRefreshLoadMoreRecyclerView(Context context, AttributeSet attrs) { super(context, attrs); initView(context); } public AlxRefreshLoadMoreRecyclerView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); initView(context); } public void setAdapter(AlxDragRecyclerViewAdapter adapter){ super.setAdapter(adapter); this.adapter = adapter; } public boolean ismPullLoading() { return mPullLoading; } public boolean ismIsRefreshing() { return mIsRefreshing; } private void updateFooterHeight(float delta) { if(mFooterView==null)return; int bottomMargin = mFooterView.getBottomMargin(); // Log.i("Alex3","初始delta是"+delta); if(delta>50)delta = delta/6; if(delta>0) {//越往下滑越难滑 if(bottomMargin>maxPullHeight)delta = delta*0.65f; else if(bottomMargin>maxPullHeight * 0.83333f)delta = delta*0.7f; else if(bottomMargin>maxPullHeight * 0.66667f)delta = delta*0.75f; else if(bottomMargin>maxPullHeight >> 1)delta = delta*0.8f; else if(bottomMargin>maxPullHeight * 0.33333f)delta = delta*0.85f; else if(bottomMargin>maxPullHeight * 0.16667F && delta > 20)delta = delta*0.2f;//如果是因为惯性向下迅速的俯冲 else if(bottomMargin>maxPullHeight * 0.16667F)delta = delta*0.9f; // Log.i("Alex3","bottomMargin是"+mFooterView.getBottomMargin()+" delta是"+delta); } int height = mFooterView.getBottomMargin() + (int) (delta+0.5); if (mEnablePullLoad && !mPullLoading) { if (height > 150){//必须拉超过一定距离才加载更多 // if (height > 1){//立即刷新 mFooterView.setState(CustomDragRecyclerFooterView.STATE_READY); mIsFooterReady = true; // Log.i("Alex2", "ready"); } else { mFooterView.setState(CustomDragRecyclerFooterView.STATE_NORMAL); mIsFooterReady = false; // Log.i("Alex2", "nomal"); } } mFooterView.setBottomMargin(height); } private void resetFooterHeight() { int bottomMargin = mFooterView.getBottomMargin(); if (bottomMargin > 20) { Log.i("Alex2", "准备重置高度,margin是" + bottomMargin + "自高是" + footerHeight); this.smoothScrollBy(0,-bottomMargin); //一松手就立即开始加载 if(mIsFooterReady){ startLoadMore(); } } } public void setLoadMoreListener(LoadMoreListener listener){ this.loadMoreListener = listener; } public void initView(Context context){ layoutManager = new LinearLayoutManager(context);//自带layoutManager，请勿设置 layoutManager.setOrientation(LinearLayoutManager.VERTICAL); WindowManager wm = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE); int height = wm.getDefaultDisplay().getHeight(); layoutManager.offsetChildrenVertical(height*2);//预加载2/3的卡片 this.setLayoutManager(layoutManager); // Log.i("Alex", "屏幕密度为" + getContext().getResources().getDisplayMetrics().density); maxPullHeight = dp2px(getContext().getResources().getDisplayMetrics().density,MAX_PULL_LENGTH);//最多下拉150dp this.footerClickListener = new footerViewClickListener(); this.addOnScrollListener(new RecyclerView.OnScrollListener() { @Override public void onScrollStateChanged(RecyclerView recyclerView, int newState) { super.onScrollStateChanged(recyclerView, newState); switch (newState){ case RecyclerView.SCROLL_STATE_IDLE: // Log.i("Alex2", "停下了||放手了"); if(isBottom)resetFooterHeight(); break; case RecyclerView.SCROLL_STATE_DRAGGING: // Log.i("Alex2", "开始拖了,现在margin是" + (mFooterView == null ? "" : mFooterView.getBottomMargin())); break; case RecyclerView.SCROLL_STATE_SETTLING: // Log.i("Alex2", "开始惯性移动"); break; } } @Override public void onScrolled(RecyclerView recyclerView, int dx, int dy) { super.onScrolled(recyclerView, dx, dy); int lastItemPosition = layoutManager.findLastVisibleItemPosition(); // Log.i("Alex2","mEnable是"+mEnablePullLoad+"lastitemPosition是"+lastItemPosition+" itemcount是"+layoutManager.getItemCount()); if(lastItemPosition == layoutManager.getItemCount()-1 && mEnablePullLoad) {//如果到了最后一个 isBottom = true; mFooterView = (CustomDragRecyclerFooterView)layoutManager.findViewByPosition(layoutManager.findLastVisibleItemPosition());//一开始还不能hide，因为hide得到最后一个可见的就不是footerview了 // Log.i("Alex2","到底啦！！"+"mfooterView是"+mFooterView); if(mFooterView!=null) mFooterView.setOnClickListener(footerClickListener); if(footerHeight==-1 && mFooterView!=null){ mFooterView.show(); mFooterView.setState(CustomDragRecyclerFooterView.STATE_NORMAL); footerHeight = mFooterView.getMeasuredHeight();//这里的测量一般不会出问题 // Log.i("Alex2", "底部高度为" + footerHeight); } updateFooterHeight(dy); }else if(lastItemPosition == layoutManager.getItemCount()-1 && mEnablePullLoad){//如果到了倒数第二个 startLoadMore();//开始加载更多 } else { isBottom = false; } } }); } /** * 设置是否开启上拉加载更多的功能 * * @param enable */ public void setPullLoadEnable(boolean enable) { mPullLoading = false; mEnablePullLoad = enable; if(adapter!=null)adapter.setPullLoadMoreEnable(enable);//adapter和recyclerView要同时设置 if(mFooterView==null)return; if (!mEnablePullLoad) { // this.smoothScrollBy(0,-footerHeight); mFooterView.hide(); mFooterView.setOnClickListener(null); mFooterView.setBottomMargin(0); //make sure "pull up" don't show a line in bottom when listview with one page } else { mFooterView.show(); mFooterView.setState(CustomDragRecyclerFooterView.STATE_NORMAL); mFooterView.setVisibility(VISIBLE); //make sure "pull up" don't show a line in bottom when listview with one page // both "pull up" and "click" will invoke load more. mFooterView.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { startLoadMore(); } }); } } /** * 停止loadmore */ public void stopLoadMore() { if (mPullLoading == true) { mPullLoading = false; if(mFooterView==null)return; mFooterView.show(); mFooterView.setState(CustomDragRecyclerFooterView.STATE_ERROR); } } private void startLoadMore() { if(mPullLoading)return; mPullLoading = true; if(mFooterView!=null)mFooterView.setState(CustomDragRecyclerFooterView.STATE_LOADING); Log.i("Alex2", "现在开始加载"); mIsFooterReady = false; if (loadMoreListener != null) { loadMoreListener.onLoadMore(); } } /** * 在刷新时要执行的方法 */ public interface LoadMoreListener{ public void onLoadMore(); } /** * 点击loadMore后要执行的事件 */ class footerViewClickListener implements OnClickListener { @Override public void onClick(View v) { startLoadMore(); } } private void updateHeaderHeight(float delta) { mHeaderView = (CustomDragHeaderView) layoutManager.findViewByPosition(0); // Log.i("Alex2", "现在在头部！！！！ header自高是" + mHeaderView.getHeight() + " margin 是" + mHeaderView.getTopMargin());//自高一般不会算错 // Log.i("Alex2", "正在设置margin" + mHeaderView.getTopMargin() +"delta是"+delta); if(delta>0){//如果是往下拉 int topMargin = mHeaderView.getTopMargin(); if(topMargin>maxPullHeight * 0.33333f)delta = delta*0.5f; else if(topMargin>maxPullHeight * 0.16667F)delta = delta*0.55f; else if(topMargin>0)delta = delta*0.6f; else if(topMargin<0)delta = delta*0.6f;//如果没有被完全拖出来 mHeaderView.setTopMargin(mHeaderView.getTopMargin() + (int)delta); } else{//如果是推回去 if(!mIsRefreshing || mHeaderView.getTopMargin()>0) {//在刷新的时候不把margin设为负值以在惯性滑动的时候能滑回去 this.scrollBy(0, (int) delta);//禁止既滚动，又同时减少触摸 // Log.i("Alex2", "正在往回推" + delta); mHeaderView.setTopMargin(mHeaderView.getTopMargin() + (int) delta); } } if(mHeaderView.getTopMargin()>0 && !mIsRefreshing){ mIsHeaderReady = true; mHeaderView.setState(CustomDragHeaderView.STATE_READY); }//设置为ready状态 else if(!mIsRefreshing){ mIsHeaderReady = false; mHeaderView.setState(CustomDragHeaderView.STATE_NORMAL); }//设置为普通状态并且缩回去 } @Override public void smoothScrollToPosition(final int position) { super.smoothScrollToPosition(position); final Timer scrollTimer = new Timer(); TimerTask timerTask = new TimerTask() { @Override public void run() { int bottomCardPosition = layoutManager.findLastVisibleItemPosition(); if(bottomCardPosition<position+1){//如果要向下滚 handler.post(new Runnable() { @Override public void run() { smoothScrollBy(0,50); } }); }else if(bottomCardPosition>position){//如果要向上滚 handler.post(new Runnable() { @Override public void run() { smoothScrollBy(0,-50); } }); }else { if(scrollTimer!=null)scrollTimer.cancel(); } } }; scrollTimer.schedule(timerTask,0,20); } /** * 在用户非手动强制刷新的时候，通过一个动画把头部一点点冒出来 */ private void smoothShowHeader(){ if(mHeaderView==null)return; // if(layoutManager.findFirstVisibleItemPosition()!=0){//如果刷新完毕的时候用户没有注视header // mHeaderView.setTopMargin(0); // return; // } if(timer!=null)timer.cancel(); final TimerTask timerTask = new TimerTask() { @Override public void run() { if(mHeaderView==null){ if(timer!=null)timer.cancel(); return; } // Log.i("Alex2","topMargin是"+mHeaderView.getTopMargin()+" height是"+mHeaderView.getHeight()); if(mHeaderView.getTopMargin()<0){ handler.post(new Runnable() { @Override public void run() { if (mIsRefreshing) {//如果目前是ready状态或者正在刷新状态 mHeaderView.setTopMargin(mHeaderView.getTopMargin() +2); } } }); } else if(timer!=null){//如果已经完全缩回去了，但是动画还没有结束，就结束掉动画 timer.cancel(); } } }; timer = new Timer(); timer.scheduleAtFixedRate(timerTask,0,16); } /** * 在用户松手的时候让头部自动收缩回去 */ private void resetHeaderHeight() { if(mHeaderView==null)mHeaderView = (CustomDragHeaderView) layoutManager.findViewByPosition(0); if(layoutManager.findFirstVisibleItemPosition()!=0){//如果刷新完毕的时候用户没有注视header mHeaderView.setTopMargin(-mHeaderView.getRealHeight()); return; } if(timer!=null)timer.cancel(); final TimerTask timerTask = new TimerTask() { @Override public void run() { if(mHeaderView==null)return; // Log.i("Alex2","topMargin是"+mHeaderView.getTopMargin()+" height是"+mHeaderView.getHeight()); if(mHeaderView.getTopMargin()>-mHeaderView.getRealHeight()){//如果header没有完全缩回去 handler.post(new Runnable() { @Override public void run() { if (mIsHeaderReady || mIsRefreshing) {//如果目前是ready状态或者正在刷新状态 // Log.i("Alex2", "现在是ready状态"); int delta = mHeaderView.getTopMargin() / 9; if (delta < 5) delta = 5; if (mHeaderView.getTopMargin() > 0) mHeaderView.setTopMargin(mHeaderView.getTopMargin() - delta); } else {//如果是普通状态 // Log.i("Alex2", "现在是普通状态"); mHeaderView.setTopMargin(mHeaderView.getTopMargin() - 5); } } }); } else if(timer!=null){//如果已经完全缩回去了，但是动画还没有结束，就结束掉动画 timer.cancel(); handler.post(new Runnable() { @Override public void run() { mHeaderView.setState(mHeaderView.STATE_FINISH); } }); } } }; timer = new Timer(); timer.scheduleAtFixedRate(timerTask,0,10); } /** * 头部是通过onTouchEvent控制的 * @param event * @return */ @Override public boolean onTouchEvent(MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_MOVE: int delta = (int)(event.getY()-oldY); oldY = event.getY(); if (layoutManager.findViewByPosition(0) instanceof CustomDragHeaderView) { isHeader = true; updateHeaderHeight(delta);//更新margin高度 }else{ isHeader = false; if(mHeaderView!=null && !mIsRefreshing)mHeaderView.setTopMargin(-mHeaderView.getRealHeight()); } break; // case MotionEvent.ACTION_DOWN: // Log.i("Alex", "touch down"); // oldY = event.getY(); // if(timer!=null)timer.cancel(); // break; case MotionEvent.ACTION_UP: // Log.i("Alex", "抬手啦！！！！ touch up "); if(mIsHeaderReady && !mIsRefreshing)startRefresh(); if(isHeader)resetHeaderHeight();//抬手之后恢复高度 break; case MotionEvent.ACTION_CANCEL: // Log.i("Alex", "touch cancel"); break; } return super.onTouchEvent(event); } /** * 因为设置了子元素的onclickListener之后，ontouch方法的down失效，所以要在分发前获取手指的位置 * @param ev * @return */ @Override public boolean dispatchTouchEvent(MotionEvent ev) { // TODO Auto-generated method stub switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: // Log.i("Alex", "touch down分发前"); oldY = ev.getY(); if (timer != null) timer.cancel(); break; } return super.dispatchTouchEvent(ev); } public void setOnRefreshListener(OnRefreshListener listener){ this.refreshListener = listener; } /** * 设置是否支持下啦刷新的功能 * * @param enable */ public void setPullRefreshEnable(boolean enable) { mIsRefreshing = false; mEnablePullRefresh = enable; if(mHeaderView==null)return; if (!mEnablePullRefresh) { mHeaderView.setOnClickListener(null); } else { mHeaderView.setState(CustomDragFooterView.STATE_NORMAL); mHeaderView.setVisibility(VISIBLE); } } /** * 停止下拉刷新，并且通过动画让头部自己缩回去 */ public void stopRefresh() { if (mIsRefreshing == true) { mIsRefreshing = false; mIsHeaderReady = false; if(mHeaderView==null)return; mHeaderView.setState(CustomDragFooterView.STATE_NORMAL); resetHeaderHeight(); } } /** * 在用户没有用手控制的情况下，通过动画把头部露出来并且执行刷新 */ public void forceRefresh(){ if(mHeaderView==null)mHeaderView = (CustomDragHeaderView) layoutManager.findViewByPosition(0); if(mHeaderView!=null)mHeaderView.setState(CustomDragHeaderView.STATE_REFRESHING); mIsRefreshing = true; Log.i("Alex2", "现在开始强制刷新"); mIsHeaderReady = false; smoothShowHeader(); if (refreshListener != null)refreshListener.onRefresh(); } private void startRefresh() { mIsRefreshing = true; mHeaderView.setState(CustomDragHeaderView.STATE_REFRESHING); Log.i("Alex2", "现在开始加载"); mIsHeaderReady = false; if (refreshListener != null) refreshListener.onRefresh(); } public interface OnRefreshListener{ public void onRefresh(); } /** * 适用于本recycler的头部下拉刷新view */ public static class CustomDragHeaderView extends LinearLayout { public final static int STATE_NORMAL = 0; public final static int STATE_READY = 1; public final static int STATE_REFRESHING = 2; public final static int STATE_FINISH = 3; public float screenDensity; private final int ROTATE_ANIM_DURATION = 180; private Context mContext; private View mContentView; private View mProgressBar; private ImageView mArrowImageView; private TextView mHintTextView; private Animation mRotateUpAnim; private Animation mRotateDownAnim; public CustomDragHeaderView(Context context) { super(context); initView(context); } public CustomDragHeaderView(Context context, AttributeSet attrs) { super(context, attrs); initView(context); } private int mState; public void setState(int state) { if (state == mState) return; if (state == STATE_REFRESHING) { // 显示进度 mArrowImageView.clearAnimation(); mArrowImageView.setVisibility(View.INVISIBLE); mProgressBar.setVisibility(View.VISIBLE); } else { // 显示箭头图片 mArrowImageView.setVisibility(View.VISIBLE); mProgressBar.setVisibility(View.INVISIBLE); } switch (state) { case STATE_NORMAL: if (mState == STATE_READY) { mArrowImageView.startAnimation(mRotateDownAnim); mHintTextView.setText(R.string.xlistview_header_hint_normal); } else if (mState == STATE_REFRESHING) {//如果是从刷新状态过来 // mArrowImageView.clearAnimation(); mArrowImageView.setVisibility(INVISIBLE); mHintTextView.setText("load completed"); } break; case STATE_READY: if (mState != STATE_READY) { mArrowImageView.clearAnimation(); mArrowImageView.startAnimation(mRotateUpAnim); } mHintTextView.setText(R.string.xlistview_header_hint_ready); break; case STATE_REFRESHING: mHintTextView.setText(R.string.xlistview_header_hint_loading); break; case STATE_FINISH: mArrowImageView.setVisibility(View.VISIBLE); mHintTextView.setText(R.string.xlistview_header_hint_normal); break; default: } mState = state; } public void setTopMargin(int height) { if (mContentView==null) return ; LayoutParams lp = (LayoutParams)mContentView.getLayoutParams(); lp.topMargin = height; mContentView.setLayoutParams(lp); } // public int getTopMargin() { LayoutParams lp = (LayoutParams)mContentView.getLayoutParams(); return lp.topMargin; } public void setHeight(int height){ if (mContentView==null) return ; LayoutParams lp = (LayoutParams)mContentView.getLayoutParams(); lp.height = height; mContentView.setLayoutParams(lp); } private int realHeight; /** * 得到这个headerView真实的高度，而且这个高度是自己定的 * @return */ public int getRealHeight(){ return realHeight; } private void initView(Context context) { mContext = context; this.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));//recyclerView里不加这句话的话宽度就会比较窄 LinearLayout moreView = (LinearLayout) LayoutInflater.from(mContext).inflate(R.layout.xlistview_header, null); addView(moreView); moreView.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT)); mContentView = moreView.findViewById(R.id.xlistview_header_content); LayoutParams lp = (LayoutParams)mContentView.getLayoutParams(); Log.i("Alex", "初始height是" + mContentView.getHeight()); lp.height = 150;//手动设置高度,如果要手动加载更多的时候才设置 screenDensity = getContext().getResources().getDisplayMetrics().density;//设置屏幕密度，用来px向dp转化 lp.height = dp2px(screenDensity,HEADER_HEIGHT);//头部高度75dp realHeight = lp.height; lp.topMargin = -lp.height; mContentView.setLayoutParams(lp); mArrowImageView = (ImageView) findViewById(R.id.xlistview_header_arrow); mHintTextView = (TextView) findViewById(R.id.xlistview_header_hint_textview); mHintTextView.setPadding(0,dp2px(screenDensity,3),0,0);//不知道为什么这个文字总会向上偏一下，所以要补回来 mProgressBar = findViewById(R.id.xlistview_header_progressbar); mRotateUpAnim = new RotateAnimation(0.0f, -180.0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); mRotateUpAnim.setDuration(ROTATE_ANIM_DURATION); mRotateUpAnim.setFillAfter(true); mRotateDownAnim = new RotateAnimation(-180.0f, 0.0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); mRotateDownAnim.setDuration(ROTATE_ANIM_DURATION); mRotateDownAnim.setFillAfter(true); } } public static int dp2px(float density, int dp) { if (dp == 0) { return 0; } return (int) (dp * density + 0.5f); } public static class CustomDragRecyclerFooterView extends LinearLayout { public final static int STATE_NORMAL = 0; public final static int STATE_READY = 1; public final static int STATE_LOADING = 2; public final static int STATE_ERROR = 3; private Context mContext; private View mContentView; private View mProgressBar; private TextView mHintView; public CustomDragRecyclerFooterView(Context context) { super(context); initView(context); } public CustomDragRecyclerFooterView(Context context, AttributeSet attrs) { super(context, attrs); initView(context); } public void setState(int state) { mProgressBar.setVisibility(View.INVISIBLE); // mHintView.setVisibility(View.INVISIBLE); if (state == STATE_READY) { mHintView.setVisibility(View.VISIBLE); mHintView.setText("松手加载更多"); } else if (state == STATE_LOADING) { mProgressBar.setVisibility(View.VISIBLE); mHintView.setVisibility(INVISIBLE); } else if(state == STATE_ERROR){ mProgressBar.setVisibility(GONE); mHintView.setVisibility(VISIBLE); mHintView.setText(R.string.xlistview_footer_hint_ready); } else { mHintView.setVisibility(View.VISIBLE); mHintView.setText(R.string.xlistview_footer_hint_normal); mHintView.setText("Load more"); } } public void setBottomMargin(int height) { if (height < 0) return ; LayoutParams lp = (LayoutParams)mContentView.getLayoutParams(); lp.bottomMargin = height; mContentView.setLayoutParams(lp); } public int getBottomMargin() { LayoutParams lp = (LayoutParams)mContentView.getLayoutParams(); return lp.bottomMargin; } /** * normal status */ public void normal() { mHintView.setVisibility(View.VISIBLE); mProgressBar.setVisibility(View.GONE); } /** * loading status */ public void loading() { mHintView.setVisibility(View.GONE); mProgressBar.setVisibility(View.VISIBLE); } /** * hide footer when disable pull load more */ public void hide() { LayoutParams lp = (LayoutParams)mContentView.getLayoutParams(); lp.height = 1;//这里如果设为0那么layoutManger就会抓不到 mContentView.setLayoutParams(lp); mContentView.setBackgroundColor(Color.BLACK);//这里的颜色要和自己的背景色一致 } /** * show footer */ public void show() { LayoutParams lp = (LayoutParams)mContentView.getLayoutParams(); lp.height = LayoutParams.WRAP_CONTENT; lp.width = LayoutParams.MATCH_PARENT; mContentView.setLayoutParams(lp); mContentView.setBackgroundColor(Color.WHITE);//这里的颜色要和自己的背景色一致 } private void initView(Context context) { mContext = context; this.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT)); LinearLayout moreView = (LinearLayout) LayoutInflater.from(mContext).inflate(R.layout.layout_customdragfooterview, null); addView(moreView); moreView.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT)); mContentView = moreView.findViewById(R.id.rlContentView); mProgressBar = moreView.findViewById(R.id.pbContentView); mHintView = (TextView)moreView.findViewById(R.id.ctvContentView); mHintView.setText("load more"); // mProgressBar.setVisibility(VISIBLE);//一直会显示转圈，自动加载更多时使用 } } /** * 为了防止代码上的混乱，使用这个recyclerView自己内置的一个adapter * @param <T> */ public static abstract class AlxDragRecyclerViewAdapter<T> extends RecyclerView.Adapter<RecyclerView.ViewHolder>{ protected static final int TYPE_HEADER = 436874; protected static final int TYPE_ITEM = 256478; protected static final int TYPE_FOOTER = 9621147; private int ITEM; private ViewHolder vhItem; protected boolean loadMore; private List<T> dataList; public List<T> getDataList() { return dataList; } public void setDataList(List<T> dataList) { this.dataList = dataList; } public AlxDragRecyclerViewAdapter(List<T> dataList,int itemLayout,boolean pullEnable){ this.dataList = dataList; this.ITEM = itemLayout; this.loadMore = pullEnable; } public abstract ViewHolder setItemViewHolder(View itemView); private T getObject(int position){ if(dataList!=null && dataList.size()>=position)return dataList.get(position-1);//如果有header return null; } @Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { if (viewType == TYPE_ITEM) { //inflate your layout and pass it to view holder View itemView = LayoutInflater.from(parent.getContext()).inflate(ITEM,null); Log.i("Alex","itemView是"+itemView); this.vhItem = setItemViewHolder(itemView); Log.i("Alex","vhItem是"+vhItem); return vhItem; } else if (viewType == TYPE_HEADER) { //inflate your layout and pass it to view holder View headerView = new CustomDragHeaderView(parent.getContext()); return new VHHeader(headerView); } else if(viewType==TYPE_FOOTER){ CustomDragRecyclerFooterView footerView = new CustomDragRecyclerFooterView(parent.getContext()); return new VHFooter(footerView); } throw new RuntimeException("there is no type that matches the type " + viewType + " + make sure your using types correctly"); } public void setPullLoadMoreEnable(boolean enable){ this.loadMore = enable; } public boolean getPullLoadMoreEnable(){return loadMore;} @Override public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {//相当于getView Log.i("Alex","正在绑定"+position+" "+holder.getClass()); if (vhItem!=null && holder.getClass() == vhItem.getClass()) { //cast holder to VHItem and set data initItemView(holder,position,getObject(position)); }else if (holder instanceof AlxDragRecyclerViewAdapter.VHHeader) { //cast holder to VHHeader and set data for header. }else if(holder instanceof AlxDragRecyclerViewAdapter.VHFooter){ if(!loadMore)((VHFooter)holder).footerView.hide();//第一次初始化显示的时候要不要显示footerView } } @Override public int getItemCount() { return (dataList==null ||dataList.size()==0)?1:dataList.size() + 2;//如果有header,若list不存在或大小为0就没有footView，反之则有 }//这里要考虑到头尾部，多以要加2 /** * 根据位置判断这里该用哪个ViewHolder * @param position * @return */ @Override public int getItemViewType(int position) { if (position == 0)return TYPE_HEADER; else if(isPositonFooter(position))return TYPE_FOOTER; return TYPE_ITEM; } protected boolean isPositonFooter(int position){//这里的position从0算起 if (dataList == null && position == 1) return true;//如果没有item return position == dataList.size() + 1;//如果有item(也许为0) } // class VHItem extends RecyclerView.ViewHolder { // public VHItem(View itemView) { // super(itemView); // } // public View getItemView(){return itemView;} // } // protected class VHHeader extends RecyclerView.ViewHolder { public VHHeader(View headerView) { super(headerView); } } protected class VHFooter extends RecyclerView.ViewHolder { public CustomDragRecyclerFooterView footerView; public VHFooter(View itemView) { super(itemView); footerView = (CustomDragRecyclerFooterView)itemView; } } public abstract void initItemView(ViewHolder itemHolder,int posion,T entity); } }