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如何在Android项目中使用RecyclerView实现上拉或下拉刷新功能

这篇文章给大家介绍如何在Android项目中使用RecyclerView实现上拉或下拉刷新功能，内容非常详细，感兴趣的小伙伴们可以参考借鉴，希望对大家能有所帮助。

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首页布局：activity_notice

 <?xml version="1.0" encoding="utf-8"?>

子item布局：item_base

<?xml version="1.0" encoding="utf-8"?>

脚布局 item_foot

<?xml version="1.0" encoding="utf-8"?>

toolbar

<?xml version="1.0" encoding="utf-8"?>

首页 MainActivity

package com.lxl.refresh;

import android.os.Bundle;
import android.os.Handler;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import butterknife.ButterKnife;
import butterknife.InjectView;

/**
 * Description：
 * Author：lxl
 * Date： 2016/10/9 10:15
 */
public class MainActivity extends AppCompatActivity {


  @InjectView(R.id.toolbar)
  Toolbar toolbar;
  @InjectView(R.id.recyclerView)
  RecyclerView recyclerView;
  @InjectView(R.id.SwipeRefreshLayout)
  SwipeRefreshLayout swipeRefreshLayout;
  boolean isSlidingToLast = false; //判断滚动状态
  boolean isLoading;
  private List> data = new ArrayList<>();
  private RecyclerViewAdapter adapter = new RecyclerViewAdapter(this, data);
  private Handler handler = new Handler();

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_notice);
    ButterKnife.inject(this);
    initView();
    Map map = new HashMap<>();
    initData();
  }

  public void initView() {
    setSupportActionBar(toolbar);
    toolbar.setTitle(R.string.notice);
    toolbar.setNavigationOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        finish();
      }
    });

    swipeRefreshLayout.setColorSchemeResources(R.color.blueStatus);
    swipeRefreshLayout.post(new Runnable() {
      @Override
      public void run() {
        swipeRefreshLayout.setRefreshing(true);
      }
    });

    swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
      @Override
      public void onRefresh() {
        handler.postDelayed(new Runnable() {
          @Override
          public void run() {
            data.clear();
            getData();
          }
        }, 2000);
      }
    });
    final LinearLayoutManager layoutManager = new LinearLayoutManager(this);
    recyclerView.setLayoutManager(layoutManager);
    recyclerView.setAdapter(adapter);
    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {

      @Override
      public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);
        Log.d("test", "StateChanged = " + newState); //滑动状态改变时触发有0,1,2三种状态


      }

      @Override
      public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        if (dy > 0) {
          //大于0表示正在向下滚动
          isSlidingToLast = true;
        } else {
          //小于等于0表示停止或向上滚动
          isSlidingToLast = false;
        }
        Log.d("test", "onScrolled"); //当RecyclerView滑动时触发类似点击事件的MotionEvent.ACTION_MOVE
        int lastVisibleItemPosition = layoutManager.findLastVisibleItemPosition();
        if (lastVisibleItemPosition + 1 == adapter.getItemCount()&& isSlidingToLast) {
          Log.d("test", "loading executed");//当且仅当滑动到最后一项并且手指上拉抛出时才执行

          boolean isRefreshing = swipeRefreshLayout.isRefreshing();
          Log.d("test", "hahh"+isRefreshing);
          if (isRefreshing) { //如何在下拉刷新则隐藏脚布局并且返回
            adapter.notifyItemRemoved(adapter.getItemCount());
            return;
          }
          if (!isLoading) {
            isLoading = true;
            handler.postDelayed(new Runnable() {
              @Override
              public void run() {
                getData(); //延时执行加载
                Log.d("test", "load more completed");
                isLoading = false;
              }
            }, 1000);
          }
        }
      }
    });

    //添加点击事件
    adapter.setOnItemClickListener(new RecyclerViewAdapter.OnItemClickListener() {
      @Override
      public void onItemClick(View view, int position) {
        Log.d("test", "item position = " + position);
      }

      @Override
      public void onItemLongClick(View view, int position) {

      }
    });
  }


  public void initData() { //第一次进来的时候加载数据
    handler.postDelayed(new Runnable() {
      @Override
      public void run() {
        getData();
      }
    }, 1500);

  }

  /**
   * 获取测试数据
   */
  private void getData() {
    for (int i = 0; i < 6; i++) { //每次加载六条数据
      Map map = new HashMap<>();
      data.add(map);
    }
    adapter.notifyDataSetChanged();
    swipeRefreshLayout.setRefreshing(false); //加载数据后收起下拉刷新
    Log.d("test", adapter.getItemCount()+"");

//    adapter.notifyItemRemoved(adapter.getItemCount()); //加载数据后上拉刷新的脚布局移除掉

//    adapter.footerHolder.ll.setVisibility(View.GONE);
    //加载数据后上拉刷新的脚布局隐藏掉
    adapter.setmCreateViewHolder(new RecyclerViewAdapter.onHolderCreate() {
      @Override
      public void created() {
        if (isSlidingToLast==false){
          adapter.footerHolder.ll.setVisibility(View.GONE);
        }else{
          adapter.footerHolder.ll.setVisibility(View.VISIBLE);
        }
      }
    });
  }


}

在第106行中通过这三个条件判断就可以下拉刷新的执行。
RecyclerView的适配器：RecyclerViewAdapter

package com.lxl.refresh;

import android.content.Context;
import android.support.v7.widget.RecyclerView.Adapter;
import android.support.v7.widget.RecyclerView.ViewHolder;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.ProgressBar;
import android.widget.TextView;

import java.util.List;

public class RecyclerViewAdapter extends Adapter {

  private static final int TYPE_ITEM = 0;
  private static final int TYPE_FOOTER = 1;
  private Context context;
  private List data;

  protected FootViewHolder footerHolder;

  public RecyclerViewAdapter(Context context, List data) {
    this.context = context;
    this.data = data;
  }
  //-------------------------------------
  public interface onHolderCreate{ //定义一个viewholder回调接口
    void created();
  }

  public onHolderCreate getmCreateViewHolder() {
    return mCreateViewHolder;
  }

  public void setmCreateViewHolder(onHolderCreate mCreateViewHolder) {
    this.mCreateViewHolder = mCreateViewHolder;
  }

  private onHolderCreate mCreateViewHolder;

  //-------------------------------------

  public interface OnItemClickListener {
    void onItemClick(View view, int position);

    void onItemLongClick(View view, int position);
  }

  private OnItemClickListener onItemClickListener;

  public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
    this.onItemClickListener = onItemClickListener;
  }

  @Override
  public int getItemCount() {
    return data.size() == 0 ? 0 : data.size() + 1; //添加脚布局
  }

  @Override
  public int getItemViewType(int position) {
    if (position + 1 == getItemCount()) {
      return TYPE_FOOTER; //脚布局
    } else {
      return TYPE_ITEM; //普通item
    }
  }

  @Override
  public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    if (viewType == TYPE_ITEM) { //创建普通类型的item布局
      View view = LayoutInflater.from(context).inflate(R.layout.item_base, parent,
          false);
      Log.d("test", "创建普通类型的item布局");
      return new ItemViewHolder(view);
    } else if (viewType == TYPE_FOOTER) { //创建脚布局类型的item布局
      View view = LayoutInflater.from(context).inflate(R.layout.item_foot, parent,
          false);
      footerHolder=new FootViewHolder(view);
      Log.d("test", "创建脚布局类型的item布局");

      return footerHolder;
    }
    return null;
  }


  @Override
  public void onBindViewHolder(final ViewHolder holder, int position) {
    //在onCreateViewHolder执行完成后回调
    if (holder instanceof FootViewHolder){
      if (mCreateViewHolder!=null){
        mCreateViewHolder.created();
      }
    }
    if (holder instanceof ItemViewHolder) {
      //holder.tv.setText(data.get(position));
      if (onItemClickListener != null) {
        holder.itemView.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
            int position = holder.getLayoutPosition();
            onItemClickListener.onItemClick(holder.itemView, position);
          }
        });

        holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
          @Override
          public boolean onLongClick(View v) {
            int position = holder.getLayoutPosition();
            onItemClickListener.onItemLongClick(holder.itemView, position);
            return false;
          }
        });
      }
    }
  }


  static class ItemViewHolder extends ViewHolder {

    TextView tv;

    public ItemViewHolder(View view) {
      super(view);
      tv = (TextView) view.findViewById(R.id.tv_date);
    }
  }

   class FootViewHolder extends ViewHolder {
     LinearLayout ll;
     ProgressBar pb;
     TextView tv;
    public FootViewHolder(View view) {
      super(view);
      ll=(LinearLayout) view.findViewById(R.id.ll);
      pb=(ProgressBar) view.findViewById(R.id.progressBar);
      tv=(TextView) view.findViewById(R.id.tv);
    }
  }
}

在第30行定义一个借口用来通知下拉刷新后隐藏脚布局，主要在onCreateViewHolder执行完成后回调。

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