1.先构建WrapRecyclerAdapter
/**
* Description: 可以添加头部和底部的Adapter
*/
public class WrapRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private final static String TAG = "WrapRecyclerAdapter";
/**
* SparseArrays map integers to Objects. Unlike a normal array of Objects,
* there can be gaps in the indices. It is intended to be more memory efficient
* than using a HashMap to map Integers to Objects, both because it avoids
* auto-boxing keys and its data structure doesn't rely on an extra entry object
* for each mapping.
*
* SparseArray是一个<int , Object>的HashMap 比HashMap更高效
*/
private SparseArray<View> mHeaderViews;
private SparseArray<View> mFooterViews;
// 基本的头部类型开始位置 用于viewType
private static int BASE_ITEM_TYPE_HEADER = 10000000;
// 基本的底部类型开始位置 用于viewType
private static int BASE_ITEM_TYPE_FOOTER = 20000000;
/**
* 数据列表的Adapter
*/
private RecyclerView.Adapter mAdapter;
public WrapRecyclerAdapter(RecyclerView.Adapter adapter) {
this.mAdapter = adapter;
mHeaderViews = new SparseArray<>();
mFooterViews = new SparseArray<>();
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// viewType 可能就是 SparseArray 的key
if (isHeaderViewType(viewType)) {
View headerView = mHeaderViews.get(viewType);
return createHeaderFooterViewHolder(headerView);
}
if (isFooterViewType(viewType)) {
View footerView = mFooterViews.get(viewType);
return createHeaderFooterViewHolder(footerView);
}
return mAdapter.onCreateViewHolder(parent, viewType);
}
/**
* 是不是底部类型
*/
private boolean isFooterViewType(int viewType) {
int position = mFooterViews.indexOfKey(viewType);
return position >= 0;
}
/**
* 创建头部或者底部的ViewHolder
*/
private RecyclerView.ViewHolder createHeaderFooterViewHolder(View view) {
return new RecyclerView.ViewHolder(view) {
};
}
/**
* 是不是头部类型
*/
private boolean isHeaderViewType(int viewType) {
int position = mHeaderViews.indexOfKey(viewType);
return position >= 0;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (isHeaderPosition(position) || isFooterPosition(position)) {
return;
}
// 计算一下位置
final int adapterPosition = position - mHeaderViews.size();
mAdapter.onBindViewHolder(holder, adapterPosition);
// 设置点击和长按事件
if (mItemClickListener != null) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mItemClickListener.onItemClick(v, adapterPosition);
}
});
}
if (mLongClickListener != null) {
holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
return mLongClickListener.onLongClick(v, adapterPosition);
}
});
}
}
@Override
public int getItemViewType(int position) {
if (isHeaderPosition(position)) {
// 直接返回position位置的key
return mHeaderViews.keyAt(position);
}
if (isFooterPosition(position)) {
// 直接返回position位置的key
position = position - mHeaderViews.size() - mAdapter.getItemCount();
return mFooterViews.keyAt(position);
}
// 返回列表Adapter的getItemViewType 117 position = position - mHeaderViews.size();
return mAdapter.getItemViewType(position);
}
/**
* 是不是底部位置
*/
private boolean isFooterPosition(int position) {
return position >= (mHeaderViews.size() + mAdapter.getItemCount());
}
/**
* 是不是头部位置
*/
private boolean isHeaderPosition(int position) {
return position < mHeaderViews.size();
}
@Override
public int getItemCount() {
// 条数三者相加 = 底部条数 + 头部条数 + Adapter的条数
return mAdapter.getItemCount() + mHeaderViews.size() + mFooterViews.size();
}
/**
* 获取列表的Adapter
*/
private RecyclerView.Adapter getAdapter() {
return mAdapter;
}
// 添加头部
public void addHeaderView(View view) {
int position = mHeaderViews.indexOfValue(view);
if (position < 0) {
mHeaderViews.put(BASE_ITEM_TYPE_HEADER++, view);
}
notifyDataSetChanged();
}
// 添加底部
public void addFooterView(View view) {
int position = mFooterViews.indexOfValue(view);
if (position < 0) {
mFooterViews.put(BASE_ITEM_TYPE_FOOTER++, view);
}
notifyDataSetChanged();
}
// 移除头部
public void removeHeaderView(View view) {
int index = mHeaderViews.indexOfValue(view);
if (index < 0) return;
mHeaderViews.removeAt(index);
notifyDataSetChanged();
}
// 移除底部
public void removeFooterView(View view) {
int index = mFooterViews.indexOfValue(view);
if (index < 0) return;
mFooterViews.removeAt(index);
notifyDataSetChanged();
}
/**
* 解决GridLayoutManager添加头部和底部不占用一行的问题
*
* @param recycler
* @version 1.0
*/
public void adjustSpanSize(RecyclerView recycler) {
if (recycler.getLayoutManager() instanceof GridLayoutManager) {
final GridLayoutManager layoutManager = (GridLayoutManager) recycler.getLayoutManager();
layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
boolean isHeaderOrFooter =
isHeaderPosition(position) || isFooterPosition(position);
return isHeaderOrFooter ? layoutManager.getSpanCount() : 1;
}
});
}
}
/***************
* 给条目设置点击和长按事件
*********************/ 205 public OnItemClickListener mItemClickListener;
public OnLongClickListener mLongClickListener;
public void setOnItemClickListener(OnItemClickListener itemClickListener) {
this.mItemClickListener = itemClickListener;
}
public void setOnLongClickListener(OnLongClickListener longClickListener) {
this.mLongClickListener = longClickListener;
}
}
2.构建WrapRecyclerView
我们最好还是模仿ListView的结构搞就搞到西，自定义一个WrapRecyclerView，可以添加删除头部和底部View，这个就比较简单
/**
* Description: 可以添加头部和底部的RecyclerView
*/
public class WrapRecyclerView extends RecyclerView {
// 包裹了一层的头部底部Adapter
private WrapRecyclerAdapter mWrapRecyclerAdapter;
// 这个是列表数据的Adapter
private Adapter mAdapter;
// 增加一些通用功能
// 空列表数据应该显示的空View
// 正在加载数据页面，也就是正在获取后台接口页面
private View mEmptyView, mLoadingView;
public WrapRecyclerView(Context context) {
super(context);
}
public WrapRecyclerView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
public WrapRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public void setAdapter(Adapter adapter) {
// 为了防止多次设置Adapter
if (mAdapter != null) {
mAdapter.unregisterAdapterDataObserver(mDataObserver);
mAdapter = null;
}
this.mAdapter = adapter;
if (adapter instanceof WrapRecyclerAdapter) {
mWrapRecyclerAdapter = (WrapRecyclerAdapter) adapter;
} else {
mWrapRecyclerAdapter = new WrapRecyclerAdapter(adapter);
}
super.setAdapter(mWrapRecyclerAdapter);
// 注册一个观察者
mAdapter.registerAdapterDataObserver(mDataObserver);
// 解决GridLayout添加头部和底部也要占据一行
mWrapRecyclerAdapter.adjustSpanSize(this);
// 加载数据页面
if (mLoadingView != null && mLoadingView.getVisibility() == View.VISIBLE) {
mLoadingView.setVisibility(View.GONE);
}
if (mItemClickListener != null) {
mWrapRecyclerAdapter.setOnItemClickListener(mItemClickListener);
}
if (mLongClickListener != null) {
mWrapRecyclerAdapter.setOnLongClickListener(mLongClickListener);
}
}
// 添加头部
public void addHeaderView(View view) {
// 如果没有Adapter那么就不添加，也可以选择抛异常提示
// 让他必须先设置Adapter然后才能添加，这里是仿照ListView的处理方式
if (mWrapRecyclerAdapter != null) {
mWrapRecyclerAdapter.addHeaderView(view);
}
}
// 添加底部
public void addFooterView(View view) {
if (mWrapRecyclerAdapter != null) {
mWrapRecyclerAdapter.addFooterView(view);
}
}
// 移除头部
public void removeHeaderView(View view) {
if (mWrapRecyclerAdapter != null) {
mWrapRecyclerAdapter.removeHeaderView(view);
}
}
// 移除底部
public void removeFooterView(View view) {
if (mWrapRecyclerAdapter != null) {
mWrapRecyclerAdapter.removeFooterView(view);
}
}
private AdapterDataObserver mDataObserver = new AdapterDataObserver() {
@Override
public void onChanged() {
if (mAdapter == null) return;
// 观察者 列表Adapter更新 包裹的也需要更新不然列表的notifyDataSetChanged没效果
if (mWrapRecyclerAdapter != mAdapter)
mWrapRecyclerAdapter.notifyDataSetChanged();
dataChanged();
}
@Override
public void onItemRangeRemoved(int positionStart, int itemCount) {
if (mAdapter == null) return;
// 观察者 列表Adapter更新 包裹的也需要更新不然列表的notifyDataSetChanged没效果
if (mWrapRecyclerAdapter != mAdapter)
mWrapRecyclerAdapter.notifyItemRemoved(positionStart);
dataChanged();
}
@Override
public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
if (mAdapter == null) return;
// 观察者 列表Adapter更新 包裹的也需要更新不然列表的notifyItemMoved没效果
if (mWrapRecyclerAdapter != mAdapter)
mWrapRecyclerAdapter.notifyItemMoved(fromPosition, toPosition);
dataChanged();
}
@Override
public void onItemRangeChanged(int positionStart, int itemCount) {
if (mAdapter == null) return;
// 观察者 列表Adapter更新 包裹的也需要更新不然列表的notifyItemChanged没效果
if (mWrapRecyclerAdapter != mAdapter)
mWrapRecyclerAdapter.notifyItemChanged(positionStart);
dataChanged();
}
@Override
public void onItemRangeChanged(int positionStart, int itemCount, Object payload) {
if (mAdapter == null) return;
// 观察者 列表Adapter更新 包裹的也需要更新不然列表的notifyItemChanged没效果
if (mWrapRecyclerAdapter != mAdapter)
mWrapRecyclerAdapter.notifyItemChanged(positionStart, payload);
dataChanged();
}
@Override
public void onItemRangeInserted(int positionStart, int itemCount) {
if (mAdapter == null) return;
// 观察者 列表Adapter更新 包裹的也需要更新不然列表的notifyItemInserted没效果
if (mWrapRecyclerAdapter != mAdapter)
mWrapRecyclerAdapter.notifyItemInserted(positionStart);
dataChanged();
}
};
/**
* 添加一个空列表数据页面
*/ 155 public void addEmptyView(View emptyView) {
this.mEmptyView = emptyView;
}
/**
* 添加一个正在加载数据的页面
*/
public void addLoadingView(View loadingView) {
this.mLoadingView = loadingView;
mLoadingView.setVisibility(View.VISIBLE);
}
/**
* Adapter数据改变的方法
*/
private void dataChanged() {
if (mAdapter.getItemCount() == 0) {
// 没有数据
if (mEmptyView != null) {
mEmptyView.setVisibility(VISIBLE);
}
} else {
// 没有数据
if (mEmptyView != null) {
mEmptyView.setVisibility(GONE);
}
}
}
/***************
* 给条目设置点击和长按事件
*********************/
public com.zzw.framelibray.recyclerview.adapter.OnItemClickListener mItemClickListener;
public com.zzw.framelibray.recyclerview.adapter.OnLongClickListener mLongClickListener;
public void setOnItemClickListener(com.zzw.framelibray.recyclerview.adapter.OnItemClickListener itemClickListener) {
this.mItemClickListener = itemClickListener;
if (mWrapRecyclerAdapter != null) {
mWrapRecyclerAdapter.setOnItemClickListener(mItemClickListener);
}
}
public void setOnLongClickListener(com.zzw.framelibray.recyclerview.adapter.OnLongClickListener longClickListener) {
this.mLongClickListener = longClickListener;
if (mWrapRecyclerAdapter != null) {
mWrapRecyclerAdapter.setOnLongClickListener(mLongClickListener);
}
}
}
3.使用：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <com.zzw.framelibray.recyclerview.view.WrapRecyclerView android:id="@+id/wrap_recycler_view" android:layout_width="match_parent" android:layout_height="match_parent" /> </LinearLayout>
Activity
public class HeaderFooterActivity extends AppCompatActivity implements OnItemClickListener {
private WrapRecyclerView mRecyclerView;
private List<People> mData;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_recycler_view);
mRecyclerView = (WrapRecyclerView) findViewById(R.id.wrap_recycler_view);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mData =new ArrayList<>();
mData.add(new People());
mData.add(new People());
mData.add(new People());
PeopleListAdapter listAdapter = new PeopleListAdapter(this, mData);
// 添加头部和底部 需要 包裹Adapter，才能添加头部和底部
WrapRecyclerAdapter wrapRecyclerAdapter = new WrapRecyclerAdapter(listAdapter);
mRecyclerView.setAdapter(wrapRecyclerAdapter);
wrapRecyclerAdapter.setOnItemClickListener(this);
// 添加头部和底部
wrapRecyclerAdapter.addHeaderView(LayoutInflater.from(this).inflate(R.layout.layout_header,mRecyclerView,false));
wrapRecyclerAdapter.addFooterView(LayoutInflater.from(this).inflate(R.layout.layout_header,mRecyclerView,false));
}
@Override
public void onItemClick(View view, int position) {
Toast.makeText(this, "" + mData.get(position).name, Toast.LENGTH_SHORT).show();
}
class PeopleListAdapter extends CommonRecyclerAdapter<People> {
public PeopleListAdapter(Context context, List<People> datas) {
super(context, datas, R.layout.channel_list_item);
}
@Override
public void convert(ViewHolder holder, People item, int position) {
holder.setText(R.id.action_btn, item.name+position);
}
}
class People{
String name="王伟:";
}
}
原创文章，作者：Maggie-Hunter，如若转载，请注明出处：https://blog.ytso.com/3091.html