RecyclerView添加头部和底部视图的实现-白红宇

ListView是有addHeaderView和 addFooterView两个方法的.

但是作为官方推荐的ListView的升级版RecyclerView缺无法实现这两个方法。

那么如果使用RecyclerView实现这两个方法的效果该怎么做呢？

网上查询了很久，试过各种各样的实现方式，终于让我发现一个还不错的实现方法，那么就给大家推荐一下。

项目地址（别人写的，非博主的）

我看了下这个源码，很简单，即写了一个继承RecyclerView的控件，自己实现addHeaderView和addFooterView两个方法

package com.xqx.com.recyclerviewheaderdemo;import android.content.Context;import android.support.v7.widget.RecyclerView;import android.util.AttributeSet;import android.util.Log;import android.view.View;import android.view.ViewGroup;import java.util.ArrayList;import java.util.List;public class XCRecyclerView extends RecyclerView{    private ArrayList
      
        mHeaderViews = new ArrayList<>();    private ArrayList
       
         mFooterViews = new ArrayList<>();    private RecyclerView.Adapter mAdapter;    private RecyclerView.Adapter mWrapAdapter;    private static final int TYPE_HEADER = -101;    private static final int TYPE_FOOTER  = -102;    private static final int TYPE_LIST_ITEM = - 103;    public XCRecyclerView(Context context) {        this(context, null);    }    public XCRecyclerView(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public XCRecyclerView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        init(context);    }    private void init(Context context){    }    @Override    public void setAdapter(Adapter adapter) {        mAdapter = adapter;        mWrapAdapter = new WrapAdapter(mHeaderViews, mFooterViews, adapter);        super.setAdapter(mWrapAdapter);        mAdapter.registerAdapterDataObserver(mDataObserver);    }    public void addHeaderView(View view){        mHeaderViews.clear();        mHeaderViews.add(view);    }    public void addFooterView(View view){        mFooterViews.clear();        mFooterViews.add(view);    }    public int getHeaderViewsCount(){        return mHeaderViews.size();    }    public int getFooterViewsCount(){        return mFooterViews.size();    }    private final RecyclerView.AdapterDataObserver mDataObserver = new RecyclerView.AdapterDataObserver() {        @Override        public void onChanged() {            mWrapAdapter.notifyDataSetChanged();        }        @Override        public void onItemRangeChanged(int positionStart, int itemCount) {            mWrapAdapter.notifyItemRangeChanged(positionStart, itemCount);        }//        @Override//        public void onItemRangeChanged(int positionStart, int itemCount, Object payload) {//            mWrapAdapter.notifyItemRangeChanged(positionStart, itemCount, payload);//        }        @Override        public void onItemRangeInserted(int positionStart, int itemCount) {            mWrapAdapter.notifyItemRangeInserted(positionStart, itemCount);        }        @Override        public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {            mWrapAdapter.notifyItemMoved(fromPosition, toPosition);        }        @Override        public void onItemRangeRemoved(int positionStart, int itemCount) {            mWrapAdapter.notifyItemRangeRemoved(positionStart, itemCount);        }    };    private class WrapAdapter extends RecyclerView.Adapter
        
         {        private Adapter mAdapter;        private List
         
           mHeaderViews;        private List
          
            mFooterViews;        public WrapAdapter(List
           
             headerViews,List
            
              footerViews,Adapter adapter){ this.mAdapter = adapter; this.mHeaderViews = headerViews; this.mFooterViews = footerViews; } public int getHeaderCount(){ return this.mHeaderViews.size(); } public int getFooterCount(){ return this.mFooterViews.size(); } public boolean isHeader(int position){ return position >= 0 && position < this.mHeaderViews.size(); } public boolean isFooter(int position){ return position < getItemCount() && position >= getItemCount() - this.mFooterViews.size(); } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { if(viewType == TYPE_HEADER){ return new CustomViewHolder(this.mHeaderViews.get(0)); }else if(viewType == TYPE_FOOTER){ return new CustomViewHolder(this.mFooterViews.get(0)); }else{ return this.mAdapter.onCreateViewHolder(parent,viewType); } } @Override public void onBindViewHolder(ViewHolder holder, int position) { if(isHeader(position)) return; if(isFooter(position)) return; int rePosition = position - getHeaderCount(); int itemCount = this.mAdapter.getItemCount(); if(this.mAdapter != null){ if(rePosition < itemCount){ Log.v("czm","rePosition/itemCount="+rePosition+"/"+itemCount); this.mAdapter.onBindViewHolder(holder,rePosition); return; } } } @Override public long getItemId(int position) { if (this.mAdapter != null && position >= getHeaderCount()) { int rePosition = position - getHeaderCount(); int itemCount = this.mAdapter.getItemCount(); if (rePosition < itemCount) { return this.mAdapter.getItemId(rePosition); } } return -1; } @Override public int getItemViewType(int position) { if(isHeader(position)){ return TYPE_HEADER; } if(isFooter(position)){ return TYPE_FOOTER; } int rePosition = position - getHeaderCount(); int itemCount = this.mAdapter.getItemCount(); if(rePosition < itemCount){ return this.mAdapter.getItemViewType(position); } return TYPE_LIST_ITEM; } @Override public int getItemCount() { if(this.mAdapter != null){ return getHeaderCount() + getFooterCount() + this.mAdapter.getItemCount(); }else{ return getHeaderCount() + getFooterCount(); } } @Override public void registerAdapterDataObserver(AdapterDataObserver observer) { if(this.mAdapter != null){ this.mAdapter.registerAdapterDataObserver(observer); } } @Override public void unregisterAdapterDataObserver(AdapterDataObserver observer) { if(this.mAdapter != null){ this.mAdapter.unregisterAdapterDataObserver(observer); } } private class CustomViewHolder extends ViewHolder{ public CustomViewHolder(View itemView) { super(itemView); } } }}

XCRecyclerView

使用方法github里也写的清清楚楚的

private MyAdapter mAdapter;private XCRecyclerView mRecyclerView;private List
     
       mData;private View mHeaderView;private View mFooterView;@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    mData = new  ArrayList
      
       ();    for(int i = 0; i < 10 ;i++){        mData.add("item_" + i);    }    mAdapter = new MyAdapter(mData);    mRecyclerView = (XCRecyclerView) findViewById(R.id.recycler_view);    mRecyclerView.setLayoutManager(new LinearLayoutManager(this));    mHeaderView = LayoutInflater.from(this).inflate(R.layout.layout_header,mRecyclerView,false);    mFooterView = LayoutInflater.from(this).inflate(R.layout.layout_footer,mRecyclerView,false);    mRecyclerView.addHeaderView(mHeaderView);    mRecyclerView.addFooterView(mFooterView);    mRecyclerView.setAdapter(mAdapter);}

注意点：

addHeaderView之后列表的数据坐标即相应发生变化！即addHeadView一次，列表第一个数据的下坐标+1（0-->1）

adapter.notifyItemChanged();等方法的坐标类似，都要相应的变化。

比如你addHeadView()一次

那么你想更新列表第4个列表项的视图，则adapter.notifyItemChanged(3+1); 多加1 headView也算一个列表项。