实现原理是使用RecyclerView的OnTouchListener方法监听滑动 在adapter里面增加两项footview 其中date.size为显示的加载条，可以自定义，date.size+1为空白的View，我们设置其高度为0 我们通过LinearLayoutManager的 findLastVisibleItemPosition判断显示的最后一条数据，如果是空白view，表示加载条已经完全展示，松开即可刷新。
回弹效果是通过在滑动时动态改变空白view的高度，达到阻尼效果 ，回弹时再动态将其改为0，达到回弹效果，通过loading防止加载过程中滑动导致显示问题 这里的回调采用了Runnable传参
public class RefreshFootAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
// 上拉加载更多 public static final int SATUS_PULLUP_LOAD_MORE = 0;
// 正在加载中 public static final int SATUS_LOADING_MORE = 1;
public static final int SATUS_UP_LOADING_MORE = 2;
// 上拉加载更多状态-默认为0 private int load_more_status = 0;
private LayoutInflater mInflater;
private List<String> mTitles = null;
private static final int TYPE_ITEM = 0;
// 普通Item View private static final int TYPE_FOOTER = 1;
// 底部FootView private static final int TYPE_FOOTER_EMPTY = 2;
// 底部空白View private static int pagesize;
private int eview_height = 1;
private long TimeFlag;
// 回弹时间 private RecyclerView parent;
private boolean loadmare;
// 判断当前是可加载更多 private boolean loading;
// 判断是否正在加载 private int startY, nowY;
// 滑动判断 <span style="white-space:pre"> </span>//构造函数 处理滑动监听 更新等功能 public RefreshFootAdapter(Context context, RecyclerView parent, final LinearLayoutManager linearLayoutManager, int pagesize, final Runnable onloadmore) {
this.parent = parent;
this.mInflater = LayoutInflater.from(context);
this.mTitles = new ArrayList<String>();
for (int i = 0;
i < 20;
i++) {
int index = i + 1;
mTitles.add("item" + index);
}
this.pagesize = pagesize;
parent.setOnTouchListener(new OnTouchListener() {
@Override public boolean onTouch(View v, MotionEvent ev) {
// TODO Auto-generated method stub switch (ev.getAction()) {
case MotionEvent.ACTION_MOVE: nowY = (int) ev.getY();
if (RefreshFootAdapter.this.getItemCount() == linearLayoutManager .findLastVisibleItemPosition() + 1) {
if (startY == 0) {
// 按下 startY = nowY;
}
int changeY = nowY - startY;
RefreshFootAdapter.this .notifyEmptyView((int) (-changeY / 1.3f));
if (loading) {
return false;
}
RefreshFootAdapter.this .changeMoreStatus(RefreshFootAdapter.this.SATUS_UP_LOADING_MORE);
loadmare = true;
}
else {
loadmare = false;
if (loading) {
return false;
}
RefreshFootAdapter.this .changeMoreStatus(RefreshFootAdapter.this.SATUS_PULLUP_LOAD_MORE);
// 普通的滑动 startY = 0;
}
break;
case MotionEvent.ACTION_UP: RefreshFootAdapter.this.resetEmptyView();
if (loadmare) {
if (loading) {
return false;
}
else {
RefreshFootAdapter.this .changeMoreStatus(RefreshFootAdapter.this.SATUS_LOADING_MORE);
if (onloadmore != null && !loading) {
loading = true;
onloadmore.run();
}
}
}
startY = 0;
break;
default: break;
}
return false;
}
}
);
}
/** * item显示类型 * * @param parent * @param viewType * @return */ public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// 进行判断显示类型，来创建返回不同的View if (viewType == TYPE_ITEM) {
View view = mInflater.inflate(R.layout.item_recycler_layout, parent, false);
// 这边可以做一些属性设置，甚至事件监听绑定 // view.setBackgroundColor(Color.RED);
ItemViewHolder itemViewHolder = new ItemViewHolder(view);
return itemViewHolder;
}
else if (viewType == TYPE_FOOTER) {
View foot_view = mInflater.inflate( R.layout.recycler_load_more_layout, parent, false);
// 这边可以做一些属性设置，甚至事件监听绑定 // view.setBackgroundColor(Color.RED);
FootViewHolder footViewHolder = new FootViewHolder(foot_view);
return footViewHolder;
}
else if (viewType == TYPE_FOOTER_EMPTY) {
View foot_view_empty = mInflater.inflate( R.layout.recycler_load_more_layout_empty, parent, false);
// 这边可以做一些属性设置，甚至事件监听绑定 // view.setBackgroundColor(Color.RED);
FootEmptyHolder footEmptyViewHolder = new FootEmptyHolder( foot_view_empty);
return footEmptyViewHolder;
}
return null;
}
/** * 数据的绑定显示 * * @param holder * @param position */ public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder instanceof ItemViewHolder) {
((ItemViewHolder) holder).item_tv.setText(mTitles.get(position));
holder.itemView.setTag(position);
}
else if (holder instanceof FootViewHolder) {
FootViewHolder footViewHolder = (FootViewHolder) holder;
switch (load_more_status) {
case SATUS_PULLUP_LOAD_MORE: footViewHolder.foot_view_item_tv.setText("上拉加载更多...");
break;
case SATUS_LOADING_MORE: footViewHolder.foot_view_item_tv.setText("正在加载更多数据...");
break;
case SATUS_UP_LOADING_MORE: footViewHolder.foot_view_item_tv.setText("松开加载更多数据...");
break;
}
}
else if (holder instanceof FootEmptyHolder) {
FootEmptyHolder footViewHolder = (FootEmptyHolder) holder;
footViewHolder.empty.setLayoutParams(new ViewGroup.LayoutParams( 111, eview_height));
}
}
/** * 进行判断是普通Item视图还是FootView视图 * * @param position * @return */ @Override public int getItemViewType(int position) {
// 最后一个item设置为footerView if (position + 1 == getItemCount()) {
return TYPE_FOOTER_EMPTY;
}
else if (position + 2 == getItemCount()) {
return TYPE_FOOTER;
}
else {
return TYPE_ITEM;
}
}
<span style="white-space:pre"> </span>//如果是页数的倍数 itemcount+2 @Override public int getItemCount() {
if (mTitles.size() % pagesize != 0) {
return mTitles.size();
}
else {
return mTitles.size() + 2;
}
// return mTitles.size()+1;
}
// 自定义的ViewHolder，持有每个Item的的所有界面元素 public static class ItemViewHolder extends RecyclerView.ViewHolder {
public TextView item_tv;
public ItemViewHolder(View view) {
super(view);
item_tv = (TextView) view.findViewById(R.id.item_tv);
}
}
/** * 底部FootView布局 */ public static class FootViewHolder extends RecyclerView.ViewHolder {
private TextView foot_view_item_tv;
public FootViewHolder(View view) {
super(view);
foot_view_item_tv = (TextView) view .findViewById(R.id.foot_view_item_tv);
}
}
<span style="white-space:pre"> </span>//空白项 public static class FootEmptyHolder extends RecyclerView.ViewHolder {
private View empty;
public FootEmptyHolder(View view) {
super(view);
empty = view.findViewById(R.id.empty);
}
}
// 添加数据 public void addItem(List<String> newDatas) {
// mTitles.add(position, data);
// notifyItemInserted(position);
newDatas.addAll(mTitles);
mTitles.removeAll(mTitles);
mTitles.addAll(newDatas);
notifyDataSetChanged();
}
<span style="white-space:pre"> </span>//更新添加数据 public void addMoreItem(List<String> newDatas) {
mTitles.addAll(newDatas);
notifyDataSetChanged();
}
<span style="white-space:pre"> </span>//更新空白项高度 private void notifyEmptyView(int height) {
this.eview_height = height;
notifyItemChanged(getItemCount() - 1);
}
<span style="white-space:pre"> </span>//空白回弹 伪回弹动画 private void resetEmptyView() {
final int dx = eview_height;
new Thread(new Runnable() {
@Override public void run() {
// TODO Auto-generated method stub final int time = 500;
final long startTime = new Date().getTime();
TimeFlag = startTime;
long nowTime = new Date().getTime();
while (startTime + time > nowTime && TimeFlag == startTime) {
nowTime = new Date().getTime();
final int dt = (int) (nowTime - startTime);
parent.post(new Runnable() {
@Override public void run() {
// TODO Auto-generated method stub eview_height = eview_height * (time - dt) / time;
notifyDataSetChanged();
}
}
);
try {
Thread.sleep(10);
}
catch (InterruptedException e) {
// TODO Auto-generated catch block e.printStackTrace();
}
}
parent.post(new Runnable() {
@Override public void run() {
// TODO Auto-generated method stub eview_height = 0;
notifyDataSetChanged();
}
}
);
}
}
).start();
}
<span style="white-space:pre"> </span>//停止加载更多 重置loading状态和显示文本 public void stopLoadMore() {
notifyDataSetChanged();
loading = false;
RefreshFootAdapter.this .changeMoreStatus(RefreshFootAdapter.this.SATUS_PULLUP_LOAD_MORE);
}
//改变加载条状态 private void changeMoreStatus(int status) {
if (loading) {
return;
}
load_more_status = status;
notifyDataSetChanged();
}
}
图1为滑动过程
图2为松开加载
以上所述是小编给大家介绍的Android RecyclerView上拉加载更多功能回弹实现代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对脚本之家网站的支持！
