Android 中RecyclerView多种item布局的写法（头布局+脚布局）

package com.anew.recyclerviewall;import android.os.Bundle;import android.os.Handler;import android.support.v7.app.AppCompatActivity;import android.support.v7.widget.DefaultItemAnimator;import android.support.v7.widget.DividerItemDecoration;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.support.v7.widget.Toolbar;import android.util.Log;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {  private RecyclerView mRecyclerView;  private List<String> mHeadList;  private List<String> mBodyList;  private List<String> mFootList;  private MyAdapter mAdapter;  private LinearLayoutManager mLayoutManager;  Handler mHandler = new Handler();  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);    setSupportActionBar(toolbar);    mHeadList = new ArrayList<>();    for (int i = 0; i < 1; i++) {      mHeadList.add("head" + i);    }    mBodyList = new ArrayList<>();    for (int i = 'A'; i < 'L'; i++) {      mBodyList.add("" + (char) i);    }    mFootList = new ArrayList<>();    for (int i = 0; i < 1; i++) {      mFootList.add("foot" + i);    }    mRecyclerView = (RecyclerView) findViewById(R.id.rv);//    使用默认的api绘制分割线    mRecyclerView.addItemDecoration        (new DividerItemDecoration(this, DividerItemDecoration.HORIZONTAL));//    设置增加删除item的动画效果    mRecyclerView.setItemAnimator(new DefaultItemAnimator());//    瀑布流//    mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(4,StaggeredGridLayoutManager.VERTICAL));    mLayoutManager = new LinearLayoutManager(this);    mRecyclerView.setLayoutManager(mLayoutManager);    mAdapter = new MyAdapter(this, mHeadList, mBodyList, mFootList);    mRecyclerView.setAdapter(mAdapter);    // 当目前的可见条目是所有数据的最后一个时，开始加载新的数据    mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {      @Override      public void onScrolled(RecyclerView recyclerView, int dx, int dy) {        super.onScrolled(recyclerView, dx, dy);        int lastCompletelyVisibleItemPosition = mLayoutManager.findLastCompletelyVisibleItemPosition();        if (lastCompletelyVisibleItemPosition + 1 == mAdapter.getItemCount()) {          mHandler.postDelayed(new Runnable() {            @Override            public void run() {              List<String> mMoreList = new ArrayList<>();              for (int i = 0; i < 3; i++) {                mMoreList.add("more" + i);              }              mBodyList.addAll(mMoreList);              mAdapter.notifyItemInserted(mAdapter.getItemCount() - 2);            }          }, 1500);          Log.e("qqq", "到底了" + lastCompletelyVisibleItemPosition);        }        int firstCompletelyVisibleItemPosition = mLayoutManager.findFirstCompletelyVisibleItemPosition();        if (firstCompletelyVisibleItemPosition == 0&&dy<0) {          Log.e("eeeee", "开始刷新呀呀呀");        }      }    });  }}

package com.anew.recyclerviewall;import android.content.Context;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;import android.widget.Toast;import java.util.List;/** * Created by a on 2017/1/7. */public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {  private Context context;  private List<String> mHeadList;  private List<String> mBodyList;  private List<String> mFootList;  private static final int HEAD_TYPE = 1;  private static final int BODY_TYPE = 2;  private static final int FOOT_TYPE = 3;  public MyAdapter(Context context, List<String> headList, List<String> bodyList, List<String> footList) {    this.context = context;    this.mHeadList = headList;    this.mBodyList = bodyList;    this.mFootList = footList;  }  //  ★ 1. 定义规则，什么情况，是哪一种ViewType  @Override  public int getItemViewType(int position) {    int viewType = -1;    if (position < getHeadCount()) {      viewType = HEAD_TYPE;    } else if (position > getHeadCount() + getBodyCount() - 1) {      //这里最后要减去1，慢慢地去数      viewType = FOOT_TYPE;    } else {      viewType = BODY_TYPE;    }    return viewType;  }  @Override  public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {    LayoutInflater inflater = LayoutInflater.from(context);    View view = null;    //  ★ 2. 根据viewType来确定加载那个布局，返回哪一个ViewHolder    switch (viewType) {      case HEAD_TYPE:        view = inflater.inflate(R.layout.item_head, parent, false);        return new HeadHolder(view);      case BODY_TYPE:        view = inflater.inflate(R.layout.item_body, parent, false);        return new BodyHolder(view);      case FOOT_TYPE:        view = inflater.inflate(R.layout.item_foot, parent, false);        return new FootHolder(view);    }    return null;  }  @Override  public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {// ★ 3. 根据holder是哪一个ViewHolder的实例，来确定操作哪一个布局的UI    if (holder instanceof HeadHolder) {      HeadHolder headHolder = (HeadHolder) holder;      headHolder.mTvHead.setText(mHeadList.get(position) + "");      headHolder.mTvHead.setOnClickListener(new View.OnClickListener() {        @Override        public void onClick(View v) {          addData();        }      });    }    if (holder instanceof BodyHolder) {      final BodyHolder bodyHolder = (BodyHolder) holder;      bodyHolder.mTvBody.setText(mBodyList.get(position - getHeadCount()) + "");      bodyHolder.mTvBody.setOnClickListener(new View.OnClickListener() {        @Override        public void onClick(View v) {          removeData(bodyHolder.getAdapterPosition());        }      });    }    if (holder instanceof FootHolder) {      final FootHolder footHolder = (FootHolder) holder;      footHolder.mTvFoot.setText(mFootList.get(position - getHeadCount() - getBodyCount()) + "");      footHolder.mTvFoot.setOnClickListener(new View.OnClickListener() {        @Override        public void onClick(View v) {          Toast.makeText(context, footHolder.getAdapterPosition() + "",              Toast.LENGTH_SHORT).show();        }      });    }  }  @Override  public int getItemCount() {    return getHeadCount() + getBodyCount() + getFootCount();  }  private int getFootCount() {    return mFootList.size();  }  private int getBodyCount() {    return mBodyList.size();  }  private int getHeadCount() {    return mHeadList.size();  }  public void addData(int position) {    mBodyList.add(position, "Insert One");//    ★★★★ 使用notifyItemInserted去更新数据，否则没有动画效果    notifyItemInserted(position);  }  /**   * 增加bodyList条目   */  public void addData() {    mBodyList.add("1");    mBodyList.add("2");    mBodyList.add("3");//    ★★★★ 使用notifyItemInserted去更新数据，否则没有动画效果    notifyItemRangeInserted(0, 3);  }  /**   * 删除bodyList条目   */  public void removeData(int position) {//    经测试疯狂点击删除条目，会产生负数，导致越界异常    if (!(position - getHeadCount() < 0)) {//    ★★★★ 防止角标越界异常，要减去头布局数量，总之去数数吧      mBodyList.remove(position - getHeadCount());      notifyItemRemoved(position);    }  }  /**   * 头布局Holder   */  static class HeadHolder extends RecyclerView.ViewHolder {    private TextView mTvHead;    public HeadHolder(View itemView) {      super(itemView);      mTvHead = (TextView) itemView.findViewById(R.id.tv_head);    }  }  /**   * 身体布局Holder   */  static class BodyHolder extends RecyclerView.ViewHolder {    private TextView mTvBody;    public BodyHolder(View itemView) {      super(itemView);      mTvBody = (TextView) itemView.findViewById(R.id.tv_body);    }  }  /**   * 脚布局Holder   */  static class FootHolder extends RecyclerView.ViewHolder {    private TextView mTvFoot;    public FootHolder(View itemView) {      super(itemView);      mTvFoot = (TextView) itemView.findViewById(R.id.tv_foot);    }  }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"       android:id="@+id/ll"       android:layout_width="match_parent"       android:layout_height="40dp"       android:layout_marginRight="11px"       android:layout_marginBottom="11px"       android:background="@color/colorPrimary"       android:orientation="vertical">  <TextView    android:id="@+id/tv_body"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:gravity="center"    android:textSize="17sp"    android:layout_gravity="center"    android:text="Hello World!"/></LinearLayout>