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