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);
}
}
