Android5.0 RecyclerView的使用
2016-11-26 本文已影响91人
markzl
刚刚开始写博客，拿一些简单出来练练手，Demo地址就不贴出来了，RecyclerView的适配器我一直都是使用CaMnter的EasyAdapter，这里贴出的地址可以参考下：https://github.com/CaMnter/EasyRecyclerView ,感觉鸿洋大神的BaseAdapter有点绕，就使用这个了。下面Adapter是随手写的...
然而
注意的地方：
- 设置布局管理器 mRecyclerView.setLayoutManager（mLayoutManager）
- LinearLayoutLayoutManager(线性布局管理器)
- StaggeredGridLayoutManager（流式布局管理器）
- 在adapter中添加item点击事件和长按事件的接口
- 添加RecyclerView上拉加载更多和下拉刷新事件监听(避免重复刷新)
- 添加item的分割线，mRecyclerView.addItemDecoration(this.mItemDecoration);下面提供继承ItemDecoration的类，不作详述
布局（layout）
\res\layout\activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.aqtc.recyclerviewdemo.MainActivity">
<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/swipe_refresh"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</android.support.v4.widget.SwipeRefreshLayout>
</RelativeLayout>
\res\layout\item_view.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="70dp">
<TextView
android:id="@+id/tv_name"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Hello, RecylerView!"
android:textSize="20sp"
android:gravity="center"
android:textColor="@color/colorPrimary"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true" />
</RelativeLayout>
代码（java）
Mainactivity
private void initView() {
mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
mSwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipe_refresh);
// mLinearLayoutManger= (LinearLayoutManager) mRecyclerView.getLayoutManager();
mLinearLayoutManger = new LinearLayoutManager(this);
}
private void initData() {
MainAdapter adapter = new MainAdapter(this);
adapter.setOnItemClickListener(new MainAdapter.OnItemClickListener() {
@Override
public void onItemClick(View convertView, int position) {
Toast.makeText(MainActivity.this,"Hello,RecyclerView!"+position,Toast.LENGTH_SHORT).show();
}
});
mRecyclerView.setLayoutManager(mLinearLayoutManger);
mRecyclerView.setAdapter(adapter);
}
private void initEvent() {
mRecyclerView.addOnScrollListener(this.getRecyclerViewOnScrollListener());
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
refreshData();
}
});
}
private void setRefreshStaus(boolean refreshStaus) {
mRefreshStaus = refreshStaus;
}
private void refreshData() {
if (mRefreshStaus) return;
Log.i("xys", "下拉加载更多");
this.setRefreshStaus(true);
mSwipeRefreshLayout.postDelayed(new Runnable() {
@Override
public void run() {
Log.i("xys", "下拉已经加载更多数据了");
mSwipeRefreshLayout.setRefreshing(false);
setRefreshStaus(false);
}
}, 2000);
}
private void getMoreData() {
if (mRefreshStaus) return;
Log.i("xys", "上拉加载更多");
this.setRefreshStaus(true);
mSwipeRefreshLayout.post(new Runnable() {
@Override
public void run() {
mSwipeRefreshLayout.setRefreshing(true);
}
});
mSwipeRefreshLayout.postDelayed(new Runnable() {
@Override
public void run() {
Log.i("xys", "上拉已经加载更多数据了");
mSwipeRefreshLayout.setRefreshing(false);
setRefreshStaus(false);
}
}, 2000);
}
public RecyclerView.OnScrollListener getRecyclerViewOnScrollListener() {
return new RecyclerView.OnScrollListener() {
private boolean toLast = false;
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
/**
* firstVisiableItem:当前可见item lastVisiableItem: 上一个可见item
* dy: 表示y轴滑动方向 dy = firstVisiableItem-lastVisiableItem>0 上拉
* dx: 表示x轴滑动方向
*/
if (dy > 0) {
//正在向下滑动/上拉
this.toLast = true;
} else {
//停止滑动或者向上滑动/下拉
this.toLast = false;
}
}
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
if (layoutManager instanceof LinearLayoutManager) {
LinearLayoutManager manager = (LinearLayoutManager) layoutManager;
//不滚动
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
//最后完成显示的item的position正好是最后一掉数据的Index
if (toLast && manager.findLastCompletelyVisibleItemPosition() == (manager.getItemCount() - 1)) {
//上拉加载更多
getMoreData();
}
}
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
StaggeredGridLayoutManager manager = (StaggeredGridLayoutManager) recyclerView.getLayoutManager();
//不滚动
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
/**
* 由于是StaggeredGridLayoutManager取最底部数据
* 可能有两个item，所以判断这之中有一个正好是最后一条数据的
* index就OK
*/
int[] bottom = manager.findLastCompletelyVisibleItemPositions(new int[2]);
int lastItemCount = manager.getItemCount() - 1;
if (toLast && (bottom[0] == lastItemCount || bottom[1] == lastItemCount)) {
//上拉加载更多
Log.i("xys", "上拉加载更多");
}
}
}
}
};
}
MainAdapter
public class MainAdapter extends RecyclerView.Adapter<MainAdapter.ViewHolder> {
private Context mContext;
private MainAdapter.OnItemClickListener onItemClickListener = null;
private MainAdapter.OnItemLongClickListener onItemLongClickListener = null;
public MainAdapter(Context context) {
mContext=context;
}
@Override
public MainAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView=LayoutInflater.from(mContext).inflate(R.layout.item_view,parent,false);
ViewHolder holder=new ViewHolder(itemView);
return holder;
}
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
holder.itemView.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
onItemClickListener.onItemClick(holder.itemView,position);
}
});
holder.setData(position);
}
@Override
public int getItemCount() {
return 50;
}
class ViewHolder extends RecyclerView.ViewHolder{
private TextView tv_name;
public ViewHolder(View itemView) {
super(itemView);
tv_name= (TextView) itemView.findViewById(R.id.tv_name);
}
public void setData(int position){
tv_name.setText("Hello, RecyclerView!"+position);
}
}
public void setOnItemClickListener(MainAdapter.OnItemClickListener onItemClickListener) {
this.onItemClickListener = onItemClickListener;
}
public void setOnItemLongClickListener(MainAdapter.OnItemLongClickListener onItemLongClickListener) {
this.onItemLongClickListener = onItemLongClickListener;
}
public interface OnItemClickListener {
void onItemClick(View convertView, int position);
}
public interface OnItemLongClickListener {
boolean onItemLongClick(View convertView, int position);
}
}
EasyBorderDividerItemDecoration(分隔线)
public class EasyBorderDividerItemDecoration extends RecyclerView.ItemDecoration {
private final int verticalItemSpacingInPx;
private final int horizontalItemSpacingInPx;
public EasyBorderDividerItemDecoration(int verticalItemSpacingInPx, int horizontalItemSpacingInPx) {
this.verticalItemSpacingInPx = verticalItemSpacingInPx;
this.horizontalItemSpacingInPx = horizontalItemSpacingInPx;
}
/**
* set border
*
* @param outRect outRect
* @param view view
* @param parent parent
* @param state state
*/
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) view.getLayoutParams();
int itemPosition = layoutParams.getViewLayoutPosition();
int childCount = parent.getAdapter().getItemCount();
int left = this.horizontalItemSpacingInPx;
int right = this.horizontalItemSpacingInPx;
int top = getItemTopSpacing(itemPosition);
int bottom = getItemBottomSpacing(itemPosition, childCount);
outRect.set(left, top, right, bottom);
}
/**
* get the item bottom spacing
*
* @param itemPosition itemPosition
* @param childCount childCount
* @return int
*/
private int getItemBottomSpacing(int itemPosition, int childCount) {
if (isLastItem(itemPosition, childCount)) {
return this.verticalItemSpacingInPx;
}
return this.verticalItemSpacingInPx / 2;
}
/**
* get the item top spacing
*
* @param itemPosition itemPosition
* @return int
*/
private int getItemTopSpacing(int itemPosition) {
if (isFirstItem(itemPosition)) {
return this.verticalItemSpacingInPx;
}
return this.verticalItemSpacingInPx / 2;
}
/**
* is the first item
*
* @param itemPosition itemPosition
* @return boolean
*/
private boolean isFirstItem(int itemPosition) {
return itemPosition == 0;
}
/**
* is the last item
*
* @param itemPosition itemPosition
* @param childCount childCount
* @return boolean
*/
private boolean isLastItem(int itemPosition, int childCount) {
return itemPosition == childCount - 1;
}
}
