首页 > 代码库 > RecyclerView实现底部载入很多其它功能
RecyclerView实现底部载入很多其它功能
这两天在公司没有什么任务分配,就研究了下咱们Google在Android5.0 推出的一个用来取代ListView的列表控件----RecyclerView。
发现功能上确实比ListView强大了不少,可扩展性也增强了不少。
可是使用过RecyclerView的Programmers应该都知道,RecyclerView无法直接代码加入头布局和脚布局。
那么他喵的怎么样实现最经常使用的底部载入很多其它数据呢?带着这种疑惑我在StackOverFlow上搜索到了一个有參考价值的答案并写了一个Demo实现了它。
參考链接附上:http://stackoverflow.com/questions/30681905/adding-items-to-endless-scroll-recyclerview-with-progressbar-at-bottom?answertab=active#tab-top
废话不多说。開始进入正题,直接上代码。
第一步:创建两个接口
public interface LoadMoreDataListener { public abstract void loadMoreData(); }
public interface RecyclerOnItemClickListener { public abstract void onClick(View view); }
第二步:依据XML中的布局来创建一个Activity
public class MainActivity extends AppCompatActivity { private RecyclerView mRecyclerView; private TextView tv_empty; private List<String> list = new ArrayList<>(); private List<String> moreData = http://www.mamicode.com/new ArrayList<>();>
activity_main
<?xml version="1.0" encoding="utf-8"?> <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:fitsSystemWindows="true" tools:context="com.byzk.loadmorerecyclerview.MainActivity"> <android.support.design.widget.AppBarLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:theme="@style/AppTheme.AppBarOverlay"> <android.support.v7.widget.Toolbar android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" android:background="?attr/colorPrimary" app:popupTheme="@style/AppTheme.PopupOverlay" /> </android.support.design.widget.AppBarLayout> <include layout="@layout/content_main" /> <android.support.design.widget.FloatingActionButton android:id="@+id/fab" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="bottom|end" android:layout_margin="@dimen/fab_margin" android:src=http://www.mamicode.com/"@android:drawable/ic_dialog_email" />>
content_main
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" app:layout_behavior="@string/appbar_scrolling_view_behavior" tools:context="com.byzk.loadmorerecyclerview.MainActivity" tools:showIn="@layout/activity_main"> <android.support.v4.widget.SwipeRefreshLayout android:id="@+id/sfl" android:layout_width="match_parent" android:layout_height="match_parent"> <android.support.v7.widget.RecyclerView android:id="@+id/mRecyclerView" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margin="5dp" android:padding="5dp" android:scrollbars="vertical"> </android.support.v7.widget.RecyclerView> </android.support.v4.widget.SwipeRefreshLayout> <TextView android:id="@+id/tv_empty" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:text="暂无数据" android:textColor="@color/colorAccent" android:visibility="gone" /> </RelativeLayout>
创建RecyclerView的条目布局 item_view<?xml version="1.0" encoding="utf-8"?> <android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android" xmlns:card_view="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="wrap_content" android:clickable="true" android:orientation="horizontal" card_view:cardUseCompatPadding="true"> <RelativeLayout android:layout_width="match_parent" android:layout_height="80dp" android:background="?android:selectableItemBackground" android:gravity="center"> <TextView android:id="@+id/tv_name" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:layout_margin="5dp" android:text="Name" android:textColor="@android:color/black" android:textSize="18sp" /> </RelativeLayout> </android.support.v7.widget.CardView>
创建脚布局item_footer<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="center" android:orientation="vertical" android:padding="10dp"> <ProgressBar android:id="@+id/pb" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout>
第三步:创建一个RecyclerView的Adapter 这一步是很关键的一步。使用过RecyclerView的programmer应该都知道它无法设置条目点击事件——!所以必须自己写一个接口回调,来自己定制点击事件。代码例如以下
/** * Author: lihongxiang * Time: 上午 11:14 * Email:lihongxiangleo@163.com */ public class MyAdapter extends RecyclerView.Adapter { private static final int VIEW_ITEM = 0; private static final int VIEW_PROG = 1; private final Context mContext; private final RecyclerView mRecyclerView; private List<String> mData; private final LayoutInflater inflater; private boolean isLoading; private int totalItemCount; private int lastVisibleItemPosition; //当前滚动的position以下最小的items的临界值 private int visibleThreshold = 5; public MyAdapter(Context context, RecyclerView recyclerView) { mContext = context; inflater = LayoutInflater.from(context); mRecyclerView = recyclerView; if (mRecyclerView.getLayoutManager() instanceof LinearLayoutManager) { final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager(); //mRecyclerView加入滑动事件监听 mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { @Override public void onScrolled(RecyclerView recyclerView, int dx, int dy) { super.onScrolled(recyclerView, dx, dy); totalItemCount = linearLayoutManager.getItemCount(); lastVisibleItemPosition = linearLayoutManager.findLastVisibleItemPosition(); Log.d("test", "totalItemCount =" + totalItemCount + "-----" + "lastVisibleItemPosition =" + lastVisibleItemPosition); if (!isLoading && totalItemCount <= (lastVisibleItemPosition + visibleThreshold)) { //此时是刷新状态 if (mMoreDataListener != null) mMoreDataListener.loadMoreData(); isLoading = true; } } }); } } public void setLoaded() { isLoading = false; } @Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { RecyclerView.ViewHolder holder; if (viewType == VIEW_ITEM) { holder = new MyViewHolder(inflater.inflate(R.layout.item_view, parent, false)); } else { holder = new MyProgressViewHolder(inflater.inflate(R.layout.item_footer, parent, false)); } return holder; }@Override public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { if (holder instanceof MyViewHolder) { if (((MyViewHolder) holder).tv_name != null) ((MyViewHolder) holder).tv_name.setText(mData.get(position)); } else if (holder instanceof MyProgressViewHolder) { if (((MyProgressViewHolder) holder).pb != null) ((MyProgressViewHolder) holder).pb.setIndeterminate(true); } } @Override public int getItemCount() { return mData =http://www.mamicode.com/= null ? 0 : mData.size();>
通过以上几部操作,就能够实现RecyclerView的底部载入很多其它的功能了,同一时候我用SwipeRefreshLayout实现了下拉刷新。今天第一次写技术博客,应该有非常多地方写的不够妥当,望各位大神们指点。实现效果例如以下!
RecyclerView实现底部载入很多其它功能