RecyclerView上拉加载,先看效果:
网上有很多这类得框架,不过在自己的项目只用到上拉加载的功能,所以自己封装一个简单点的。
主要依赖BaseRecyPRAdapter这类
public abstract class BaseRecyPRAdapter<T> extends RecyclerView.Adapter<BaseRecyPRAdapter.BaseViewHolder> { private static final String TAG = "BaseRecyPRAdapter"; public static final int VIEW_ITEM = 0; public static final int VIEW_PROG = 1; public List<T> mDataList; private final Context mContext; private final RecyclerView mRecyclerView; private int totalItemCount; private int lastVisibleItemPosition; boolean isShowFootVieW = false; private Handler handler = new Handler(); private static final int STATE_NORMAL = 0; private static final int STATE_LOADING = 1; private static final int STATE_LOAD_COMPLETE = 2; private int mState = STATE_NORMAL; public BaseRecyPRAdapter(Context context, RecyclerView recyclerView) { mContext = context; mRecyclerView = recyclerView; if (mRecyclerView.getLayoutManager() instanceof LinearLayoutManager) { final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager(); mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { @Override public void onScrollStateChanged(RecyclerView recyclerView, int newState) { super.onScrollStateChanged(recyclerView, newState); int extent = recyclerView.computeVerticalScrollExtent(); int range = recyclerView.computeVerticalScrollRange(); Log.e(TAG, "\n extent = " + extent + "\n range = " + range); if (range > extent) { if(!isShowFootVieW){ notifyDataSetChanged(); } isShowFootVieW = true; } else { isShowFootVieW = false; } totalItemCount = linearLayoutManager.getItemCount(); if (mState == STATE_NORMAL && newState == RecyclerView.SCROLL_STATE_IDLE && totalItemCount == lastVisibleItemPosition + 1 && range > extent) { mState = STATE_LOADING; handler.post(new Runnable() { @Override public void run() { if (mLoadMoreDataListener != null) { mLoadMoreDataListener.loadMoreData(); } } }); } } @Override public void onScrolled(RecyclerView recyclerView, int dx, int dy) { super.onScrolled(recyclerView, dx, dy); lastVisibleItemPosition = linearLayoutManager.findLastVisibleItemPosition(); } }); } } @Override public BaseViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { BaseViewHolder holder = null; View view = null; if (viewType == VIEW_PROG) { view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_footer, parent, false); } else { view = LayoutInflater.from(parent.getContext()).inflate(getLayoutId(viewType), parent, false); } holder = new BaseViewHolder(view); return holder; } @Override public void onBindViewHolder(BaseViewHolder holder, int position) { if (holder.getItemViewType() == BaseRecyPRAdapter.VIEW_PROG) { // LogTool.LogE_DEBUG(TAG, "onBindViewHolder--->" + mState); ProgressBar progressBar = (ProgressBar) holder.getView(R.id.progressbar); TextView text = (TextView) holder.getView(R.id.text); if (mState == STATE_LOAD_COMPLETE) { progressBar.setVisibility(View.GONE); text.setText(mContext.getString(R.string.没有数据了)); } else { progressBar.setVisibility(View.VISIBLE); text.setText(mContext.getString(R.string.正在加载中)); } } if (holder.getItemViewType() == BaseRecyPRAdapter.VIEW_ITEM) { onBindData(holder, position); } } @Override public int getItemCount() { if (isShowFootVieW) { return mDataList == null ? 0 : mDataList.size() + 1; } else { return mDataList == null ? 0 : mDataList.size(); } } //根据不同的数据返回不同的viewType @Override public int getItemViewType(int position) { if (mDataList == null) return VIEW_ITEM; if (position == mDataList.size()) { return VIEW_PROG; } else { return VIEW_ITEM; } } /** * 根据type 返回不同的布局 * * @param type * @return */ public abstract int getLayoutId(int type); public abstract void onBindData(BaseViewHolder holder, int position); public static class BaseViewHolder extends RecyclerView.ViewHolder { private Map<Integer, View> mViewMap; public View view; public BaseViewHolder(View itemView) { super(itemView); view = itemView; mViewMap = new HashMap<>(); } /** * 获取设置的view * * @param id * @return */ public View getView(int id) { View view = mViewMap.get(id); if (view == null) { view = itemView.findViewById(id); mViewMap.put(id, view); } return view; } } public void stopLoadMore() { mState = STATE_NORMAL; notifyDataSetChanged(); } public void loadComplete() { mState = STATE_LOAD_COMPLETE; notifyItemChanged(getItemCount()-1); } public void setData(List<T> datas) { mDataList = datas; } private LoadMoreDataListener mLoadMoreDataListener; public void setLoadMoreDataListener(LoadMoreDataListener mLoadMoreDataListener) { this.mLoadMoreDataListener = mLoadMoreDataListener; } public interface LoadMoreDataListener { void loadMoreData(); } }
在activity中使用:
public class MainActivity extends AppCompatActivity { private static final String TAG = "RecyActivity"; private RecyclerView mRecyclerView; private List<String> list = new ArrayList<>(); private MyRecyViewAdapter mAdapter; private Handler handler = new Handler(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); init(); } private void init() { initView(); initData(); initListener(); } private void initView() { mRecyclerView = (RecyclerView) findViewById(R.id.recyclerView); //创建一个LinearLayoutManager对象 LinearLayoutManager linearLayoutManager = new LinearLayoutManager( this, LinearLayoutManager.VERTICAL, false); mRecyclerView.setLayoutManager(linearLayoutManager); //创建adapter对象 mAdapter = new MyRecyViewAdapter(this, mRecyclerView); mRecyclerView.setAdapter(mAdapter); mAdapter.setData(list);//设置数据 } //初始化数据 private void initData() { for (int i = 0; i < 15; i++) { list.add("DATA---------->" + i); } } //初始化监听 private void initListener() { //加载更多回调监听 mAdapter.setLoadMoreDataListener(new BaseRecyPRAdapter.LoadMoreDataListener() { @Override public void loadMoreData() { //加入null值此时adapter会判断item的type Log.e(TAG, "loadMoreData--->"); handler.postDelayed(new Runnable() { @Override public void run() { if (list.size() < 30) { for (int i = 0; i < 5; i++) { list.add("LOAD MORE DATA---------->" + i); } mAdapter.stopLoadMore(); } else { mAdapter.loadComplete(); } } }, 500); } }); } class MyRecyViewAdapter extends BaseRecyPRAdapter<String> { public MyRecyViewAdapter(Context context, RecyclerView recyclerView) { super(context, recyclerView); } @Override public int getLayoutId(int type) { return R.layout.item_view; } @Override public void onBindData(BaseViewHolder holder, int position) { Log.e(TAG, "onBindData--->" + position); if (mDataList == null || mDataList.isEmpty()) return; TextView tv = (TextView) holder.getView(R.id.tv_name); if (tv != null) { tv.setText("DATA--------->" + position); } } } }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持亿速云。
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