編輯:關於Android編程
實現原理是使用RecyclerView的OnTouchListener方法監聽滑動 在adapter裡面增加兩項footview 其中date.size為顯示的加載條,可以自定義,date.size+1為空白的View,我們設置其高度為0 我們通過LinearLayoutManager的 findLastVisibleItemPosition判斷顯示的最後一條數據,如果是空白view,表示加載條已經完全展示,松開即可刷新。
回彈效果是通過在滑動時動態改變空白view的高度,達到阻尼效果 ,回彈時再動態將其改為0,達到回彈效果,通過loading防止加載過程中滑動導致顯示問題 這裡的回調采用了Runnable傳參
public class RefreshFootAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> { // 上拉加載更多 public static final int SATUS_PULLUP_LOAD_MORE = 0; // 正在加載中 public static final int SATUS_LOADING_MORE = 1; public static final int SATUS_UP_LOADING_MORE = 2; // 上拉加載更多狀態-默認為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;// 回彈時間 private RecyclerView parent; private boolean loadmare;// 判斷當前是可加載更多 private boolean loading;// 判斷是否正在加載 private int startY, nowY;// 滑動判斷 <span > </span>//構造函數 處理滑動監聽 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); // 普通的滑動 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顯示類型 * * @param parent * @param viewType * @return */ public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { // 進行判斷顯示類型,來創建返回不同的View if (viewType == TYPE_ITEM) { View view = mInflater.inflate(R.layout.item_recycler_layout, parent, false); // 這邊可以做一些屬性設置,甚至事件監聽綁定 // 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); // 這邊可以做一些屬性設置,甚至事件監聽綁定 // 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); // 這邊可以做一些屬性設置,甚至事件監聽綁定 // view.setBackgroundColor(Color.RED); FootEmptyHolder footEmptyViewHolder = new FootEmptyHolder( foot_view_empty); return footEmptyViewHolder; } return null; } /** * 數據的綁定顯示 * * @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("上拉加載更多..."); break; case SATUS_LOADING_MORE: footViewHolder.foot_view_item_tv.setText("正在加載更多數據..."); break; case SATUS_UP_LOADING_MORE: footViewHolder.foot_view_item_tv.setText("松開加載更多數據..."); break; } } else if (holder instanceof FootEmptyHolder) { FootEmptyHolder footViewHolder = (FootEmptyHolder) holder; footViewHolder.empty.setLayoutParams(new ViewGroup.LayoutParams( 111, eview_height)); } } /** * 進行判斷是普通Item視圖還是FootView視圖 * * @param position * @return */ @Override public int getItemViewType(int position) { // 最後一個item設置為footerView if (position + 1 == getItemCount()) { return TYPE_FOOTER_EMPTY; } else if (position + 2 == getItemCount()) { return TYPE_FOOTER; } else { return TYPE_ITEM; } } <span > </span>//如果是頁數的倍數 itemcount+2 @Override public int getItemCount() { if (mTitles.size() % pagesize != 0) { return mTitles.size(); } else { return mTitles.size() + 2; } // return mTitles.size()+1; } // 自定義的ViewHolder,持有每個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 > </span>//空白項 public static class FootEmptyHolder extends RecyclerView.ViewHolder { private View empty; public FootEmptyHolder(View view) { super(view); empty = view.findViewById(R.id.empty); } } // 添加數據 public void addItem(List<String> newDatas) { // mTitles.add(position, data); // notifyItemInserted(position); newDatas.addAll(mTitles); mTitles.removeAll(mTitles); mTitles.addAll(newDatas); notifyDataSetChanged(); } <span > </span>//更新添加數據 public void addMoreItem(List<String> newDatas) { mTitles.addAll(newDatas); notifyDataSetChanged(); } <span > </span>//更新空白項高度 private void notifyEmptyView(int height) { this.eview_height = height; notifyItemChanged(getItemCount() - 1); } <span > </span>//空白回彈 偽回彈動畫 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 > </span>//停止加載更多 重置loading狀態和顯示文本 public void stopLoadMore() { notifyDataSetChanged(); loading = false; RefreshFootAdapter.this .changeMoreStatus(RefreshFootAdapter.this.SATUS_PULLUP_LOAD_MORE); } //改變加載條狀態 private void changeMoreStatus(int status) { if (loading) { return; } load_more_status = status; notifyDataSetChanged(); } }
圖1為滑動過程
圖2為松開加載
以上所述是小編給大家介紹的Android RecyclerView上拉加載更多功能回彈實現代碼,希望對大家有所幫助,如果大家有任何疑問請給我留言,小編會及時回復大家的。在此也非常感謝大家對本站網站的支持!
內存洩露排查手記 Time:2013.09.02 Author:sodino 問題現象: 這裡內存洩露是指已實例化的對象長期被hold住且無法釋放或不能
在MaterialDialog 仿Android 5.0原生的AlertDialog樣式的對話框一文中以及詳細介紹了單選/多選對話框的用法,但是在現實開發中,我們可能需要
我們先來看看優酷的控件是怎麼回事? 只響應最後也就是最頂部的卡片的點擊事件,如果點擊的不是最頂部的卡片那麼就先把它放到最頂部,然後在移動到最前面來,反復如次。 知道了這
1,上圖:2,代碼:MainActivity.Javapackage com.hero.zhaoq.seekbarchangeddemo;import android.c