Android RecyclerView添加上拉加载更多效果

//普通布局的typestatic final int TYPE_ITEM = 0;//脚布局static final int TYPE_FOOTER = 1;

 @Override  public int getItemViewType(int position) {    //如果position加1正好等于所有item的总和,说明是最后一个item,将它设置为脚布局    if (position + 1 == getItemCount()) {      return TYPE_FOOTER;    } else {      return TYPE_ITEM;    }  }

 @Override  public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {    if (viewType == TYPE_ITEM) {      View view = View.inflate(mContext, R.layout.item_recycler, null);      MyViewHolder holder = new MyViewHolder(view);      return holder;    } else if (viewType == TYPE_FOOTER) {      //脚布局      View view = View.inflate(mContext, R.layout.recycler_load_more_layout, null);      FootViewHolder footViewHolder = new FootViewHolder(view);      return footViewHolder;    }    return null;  }

/**   * 改变脚布局的状态的方法,在activity根据请求数据的状态来改变这个状态   *   * @param state   */  public void changeState(int state) {    this.footer_state = state;    notifyDataSetChanged();  }

//上拉加载更多// static final int PULL_LOAD_MORE = 0;  //正在加载更多  static final int LOADING_MORE = 1;  //没有更多  static final int NO_MORE = 2;  //脚布局当前的状态,默认为没有更多  int footer_state = 1;

 @Override  public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {    if (holder instanceof MyViewHolder) {      ((MyViewHolder) holder).mTextView.setText(mList.get(position));    } else if (holder instanceof FootViewHolder) {      FootViewHolder footViewHolder = (FootViewHolder) holder;      if (position == 0) {//如果第一个就是脚布局,,那就让他隐藏        footViewHolder.mProgressBar.setVisibility(View.GONE);        footViewHolder.tv_line1.setVisibility(View.GONE);        footViewHolder.tv_line2.setVisibility(View.GONE);        footViewHolder.tv_state.setText("");      }      switch (footer_state) {//根据状态来让脚布局发生改变//        case PULL_LOAD_MORE://上拉加载//          footViewHolder.mProgressBar.setVisibility(View.GONE);//          footViewHolder.tv_state.setText("上拉加载更多");//          break;        case LOADING_MORE:          footViewHolder.mProgressBar.setVisibility(View.VISIBLE);          footViewHolder.tv_line1.setVisibility(View.GONE);          footViewHolder.tv_line2.setVisibility(View.GONE);          footViewHolder.tv_state.setText("正在加载...");          break;        case NO_MORE:          footViewHolder.mProgressBar.setVisibility(View.GONE);          footViewHolder.tv_line1.setVisibility(View.VISIBLE);          footViewHolder.tv_line2.setVisibility(View.VISIBLE);          footViewHolder.tv_state.setText("我是有底线的");          footViewHolder.tv_state.setTextColor(Color.parseColor("#ff00ff"));          break;      }    }  }

 @Override  public int getItemCount() {    return mList != null ? mList.size() + 1 : 0;  }

//给recyclerView添加滑动监听    mRecycler.addOnScrollListener(new RecyclerView.OnScrollListener() {      @Override      public void onScrollStateChanged(RecyclerView recyclerView, int newState) {        super.onScrollStateChanged(recyclerView, newState);        /*        到达底部了,如果不加!isLoading的话到达底部如果还一滑动的话就会一直进入这个方法        就一直去做请求网络的操作,这样的用户体验肯定不好.添加一个判断,每次滑倒底只进行一次网络请求去请求数据        当请求完成后,在把isLoading赋值为false,下次滑倒底又能进入这个方法了         */        if (newState == RecyclerView.SCROLL_STATE_IDLE && lastVisibleItem + 1 == mAdapter.getItemCount() && !isLoading) {          //到达底部之后如果footView的状态不是正在加载的状态,就将 他切换成正在加载的状态          if (page < totlePage) {            Log.e("duanlian", "onScrollStateChanged: " + "进来了");            isLoading = true;            mAdapter.changeState(1);            new Handler().postDelayed(new Runnable() {              @Override              public void run() {                getData();                page++;              }            }, 2000);          } else {            mAdapter.changeState(2);          }        }      }      @Override      public void onScrolled(RecyclerView recyclerView, int dx, int dy) {        super.onScrolled(recyclerView, dx, dy);        //拿到最后一个出现的item的位置        lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();      }    });

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"        android:id="@+id/ll_below"        android:layout_width="match_parent"        android:layout_height="45dp"  >  <LinearLayout    android:layout_width="fill_parent"    android:layout_height="45dp"    android:gravity="center"    android:orientation="horizontal">    <TextView      android:id="@+id/tv_line1"      android:layout_width="60dp"      android:layout_height="1dp"      android:layout_marginRight="10dp"      android:background="#ff00ff"      android:visibility="gone"/>    <ProgressBar      android:id="@+id/progressbar"      android:layout_width="25dp"      android:layout_height="25dp"      android:visibility="visible"/>    <TextView      android:id="@+id/foot_view_item_tv"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:layout_marginLeft="4dp"      android:text="上拉加载更多"/>    <TextView      android:id="@+id/tv_line2"      android:layout_width="60dp"      android:layout_height="1dp"      android:layout_marginLeft="10dp"      android:background="#ff00ff"      android:visibility="gone"/>  </LinearLayout></RelativeLayout>

package com.duanlian.recyclerviewloadmoredemo;import android.content.Context;import android.graphics.Color;import android.support.v7.widget.RecyclerView;import android.view.View;import android.view.ViewGroup;import android.widget.ProgressBar;import android.widget.TextView;import java.util.List;public class MyRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {  private Context mContext;  private List<String> mList;  //普通布局的type  static final int TYPE_ITEM = 0;  //脚布局  static final int TYPE_FOOTER = 1;  //  //上拉加载更多//  static final int PULL_LOAD_MORE = 0;  //正在加载更多  static final int LOADING_MORE = 1;  //没有更多  static final int NO_MORE = 2;  //脚布局当前的状态,默认为没有更多  int footer_state = 1;  public MyRecyclerAdapter(Context context, List<String> list) {    mContext = context;    mList = list;  }  @Override  public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {    if (viewType == TYPE_ITEM) {      View view = View.inflate(mContext, R.layout.item_recycler, null);      MyViewHolder holder = new MyViewHolder(view);      return holder;    } else if (viewType == TYPE_FOOTER) {      //脚布局      View view = View.inflate(mContext, R.layout.recycler_load_more_layout, null);      FootViewHolder footViewHolder = new FootViewHolder(view);      return footViewHolder;    }    return null;  }  @Override  public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {    if (holder instanceof MyViewHolder) {      ((MyViewHolder) holder).mTextView.setText(mList.get(position));    } else if (holder instanceof FootViewHolder) {      FootViewHolder footViewHolder = (FootViewHolder) holder;      if (position == 0) {//如果第一个就是脚布局,,那就让他隐藏        footViewHolder.mProgressBar.setVisibility(View.GONE);        footViewHolder.tv_line1.setVisibility(View.GONE);        footViewHolder.tv_line2.setVisibility(View.GONE);        footViewHolder.tv_state.setText("");      }      switch (footer_state) {//根据状态来让脚布局发生改变//        case PULL_LOAD_MORE://上拉加载//          footViewHolder.mProgressBar.setVisibility(View.GONE);//          footViewHolder.tv_state.setText("上拉加载更多");//          break;        case LOADING_MORE:          footViewHolder.mProgressBar.setVisibility(View.VISIBLE);          footViewHolder.tv_line1.setVisibility(View.GONE);          footViewHolder.tv_line2.setVisibility(View.GONE);          footViewHolder.tv_state.setText("正在加载...");          break;        case NO_MORE:          footViewHolder.mProgressBar.setVisibility(View.GONE);          footViewHolder.tv_line1.setVisibility(View.VISIBLE);          footViewHolder.tv_line2.setVisibility(View.VISIBLE);          footViewHolder.tv_state.setText("我是有底线的");          footViewHolder.tv_state.setTextColor(Color.parseColor("#ff00ff"));          break;      }    }  }  @Override  public int getItemViewType(int position) {    //如果position加1正好等于所有item的总和,说明是最后一个item,将它设置为脚布局    if (position + 1 == getItemCount()) {      return TYPE_FOOTER;    } else {      return TYPE_ITEM;    }  }  @Override  public int getItemCount() {    return mList != null ? mList.size() + 1 : 0;  }  /**   * 正常布局的ViewHolder   */  class MyViewHolder extends RecyclerView.ViewHolder {    TextView mTextView;    public MyViewHolder(View itemView) {      super(itemView);      mTextView = (TextView) itemView.findViewById(R.id.item_textView);    }  }  /**   * 脚布局的ViewHolder   */  public static class FootViewHolder extends RecyclerView.ViewHolder {    private ProgressBar mProgressBar;    private TextView tv_state;    private TextView tv_line1;    private TextView tv_line2;    public FootViewHolder(View itemView) {      super(itemView);      mProgressBar = (ProgressBar) itemView.findViewById(R.id.progressbar);      tv_state = (TextView) itemView.findViewById(R.id.foot_view_item_tv);      tv_line1 = (TextView) itemView.findViewById(R.id.tv_line1);      tv_line2 = (TextView) itemView.findViewById(R.id.tv_line2);    }  }  /**   * 改变脚布局的状态的方法,在activity根据请求数据的状态来改变这个状态   *   * @param state   */  public void changeState(int state) {    this.footer_state = state;    notifyDataSetChanged();  }}

package com.duanlian.recyclerviewloadmoredemo;import android.os.Bundle;import android.os.Handler;import android.support.v7.app.AppCompatActivity;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.util.Log;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {  private RecyclerView mRecycler;  private List<String> mList;  private List<String> list;  private MyRecyclerAdapter mAdapter;  LinearLayoutManager linearLayoutManager;  int lastVisibleItem;  int page = 0;  boolean isLoading = false;//用来控制进入getdata()的次数  int totlePage = 5;//模拟请求的一共的页数  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    initView();    getData();  }  private void initView() {    mRecycler = (RecyclerView) findViewById(R.id.recycler);    linearLayoutManager = new LinearLayoutManager(this);    mRecycler.setLayoutManager(linearLayoutManager);    mList = new ArrayList<>();    mAdapter = new MyRecyclerAdapter(this, mList);    mRecycler.setAdapter(mAdapter);    //给recyclerView添加滑动监听    mRecycler.addOnScrollListener(new RecyclerView.OnScrollListener() {      @Override      public void onScrollStateChanged(RecyclerView recyclerView, int newState) {        super.onScrollStateChanged(recyclerView, newState);        /*        到达底部了,如果不加!isLoading的话到达底部如果还一滑动的话就会一直进入这个方法        就一直去做请求网络的操作,这样的用户体验肯定不好.添加一个判断,每次滑倒底只进行一次网络请求去请求数据        当请求完成后,在把isLoading赋值为false,下次滑倒底又能进入这个方法了         */        if (newState == RecyclerView.SCROLL_STATE_IDLE && lastVisibleItem + 1 == mAdapter.getItemCount() && !isLoading) {          //到达底部之后如果footView的状态不是正在加载的状态,就将 他切换成正在加载的状态          if (page < totlePage) {            Log.e("duanlian", "onScrollStateChanged: " + "进来了");            isLoading = true;            mAdapter.changeState(1);            new Handler().postDelayed(new Runnable() {              @Override              public void run() {                getData();                page++;              }            }, 2000);          } else {            mAdapter.changeState(2);          }        }      }      @Override      public void onScrolled(RecyclerView recyclerView, int dx, int dy) {        super.onScrolled(recyclerView, dx, dy);        //拿到最后一个出现的item的位置        lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();      }    });  }  /**   * 模拟请求数据   */  private void getData() {    list = new ArrayList<>();    for (int i = 0; i < 10; i++) {      list.add("第" + i + "条");    }    mList.addAll(list);    isLoading = false;    mAdapter = new MyRecyclerAdapter(this, mList);    mRecycler.setAdapter(mAdapter);  }}