在Android项目中使用RecyclerView实现一个上拉加载下拉刷新功能

package com.example.fly.recyclerviewrefresh.base;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import com.example.fly.recyclerviewrefresh.R;
import java.util.ArrayList;
import java.util.List;

/**
 * 类名：
 * 类描述：下拉刷新和上拉加载
 * 创建人：fly
 * 创建日期： 2017/2/2.
 * 版本：V1.0
 */
public abstract class RefreshActivity<T extends Object,A extends RecyclerView.Adapter> extends BaseActivity implements SwipeRefreshLayout.OnRefreshListener {
 protected SwipeRefreshLayout swipeRefreshLayout;
 protected RecyclerView recyclerView;
 protected LinearLayoutManager linearLayoutManager;
 protected A adapter;
 protected List<T> lists = new ArrayList<>();
 protected T dataBeanLoadMore = createBean();
 protected boolean isLoadDataIng; // 默认为false 是否正在加载数据， false 不在加载， true 正在加载
 protected boolean isScrollY; // 是否在Y轴（垂直方向）上滑动， false 没滑动， true 滑动

 @Override
 protected void onCreate(@Nullable Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(setLayout());
 swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);
 swipeRefreshLayout.setOnRefreshListener(this);
 swipeRefreshLayout.setColorSchemeResources(Refresh.colors); // 设置变化的颜色
 recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
 linearLayoutManager = new LinearLayoutManager(this);
 recyclerView.setLayoutManager(linearLayoutManager);
 loadMore();
 }

 /**作用就是能在父类中初始化公共的控件如上面的onCreate(@Nullable Bundle savedInstanceState)初始化的控件*/
 protected abstract int setLayout();

 public abstract T createBean();

// public abstract A createAdapter();

 /**上拉加载*/
 protected void loadMore() {
 recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {

 /**
 *
 * @param recyclerView 当前在滚动的RecyclerView
 * @param newState 当前滚动状态
 *  newState有三种值:
 //静止,没有滚动
 public static final int SCROLL_STATE_IDLE = 0;

 //正在被外部拖拽,一般为用户正在用手指滚动
 public static final int SCROLL_STATE_DRAGGING = 1;

 //自动滚动开始
 public static final int SCROLL_STATE_SETTLING = 2;
 */
 @Override
 public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
 super.onScrollStateChanged(recyclerView, newState);
 if (newState == RecyclerView.SCROLL_STATE_IDLE && isLoadDataIng == false ) {
  int lastVisibleItem = linearLayoutManager.findLastCompletelyVisibleItemPosition(); // 获取最后一个item的角标
  int totalItemCount = linearLayoutManager.getItemCount(); // 获取item的总数
  if (lastVisibleItem == (totalItemCount - 1)) { // 判断滑到最后一个item
  if (!swipeRefreshLayout.isRefreshing()) { //不再下拉刷新状态
  if (isScrollY) { // 在Y轴（垂直方向）上有滑动
  // TODO 执行上拉加载
  onShowRefresh();
  loadMoreData();
  }
  }
  }
 }
 }

 /**
 *
 * @param recyclerView 当前滚动的view
 * @param dx 水平滚动距离
 * @param dy 垂直滚动距离
 */
 @Override
 public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
 super.onScrolled(recyclerView, dx, dy);
 if (dy > 0) {
  isScrollY = true;
 }else{
  isScrollY = false;
 }
 }
 });
 }

 /**加载数据*/
 public abstract void loadMoreData();

 /**显示加在更多的View*/
 protected void onShowRefresh() {
 isLoadDataIng = true; // 正在加载数据
 lists.add(dataBeanLoadMore);
 adapter.notifyDataSetChanged();
 }

 /**隐藏加在更多的View*/
 protected void onHintLoadMore() {
 lists.remove(dataBeanLoadMore);
 isLoadDataIng = false; // 不在加载数据
 adapter.notifyDataSetChanged();
 }
}

package com.example.fly.recyclerviewrefresh;

import android.os.Handler;
import android.os.Bundle;
import com.example.fly.recyclerviewrefresh.adapter.RecyclerAdapter;
import com.example.fly.recyclerviewrefresh.base.Refresh;
import com.example.fly.recyclerviewrefresh.base.RefreshActivity;
import com.example.fly.recyclerviewrefresh.bean.DataBean;

/**
 * 类名：
 * 类描述：RecyclerView刷新 方法二
 * 创建人：fly
 * 创建日期： 2017/2/2.
 * 版本：V1.0
 */
public class MainActivity extends RefreshActivity<DataBean,RecyclerAdapter>{

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 for (int i = 0; i < 20; i++) {
 DataBean dataBean = new DataBean(Refresh.COMMON);
 dataBean.number = String.valueOf(i);
 lists.add(dataBean);
 }
 adapter = new RecyclerAdapter(lists,this);
 recyclerView.setAdapter(adapter);
 }

 @Override
 public void onRefresh() {
 new Handler().postDelayed(new Runnable() {
 @Override
 public void run() {
 lists.clear();
 adapter.notifyDataSetChanged();
 swipeRefreshLayout.setRefreshing(false);
 }
 },1000);
 }

 @Override
 protected int setLayout() {return R.layout.activity_main;}

 @Override
 public DataBean createBean() {return new DataBean(Refresh.LOAD_MORE);}

 @Override
 public void loadMoreData() {
 for (int i = 0; i < 5; i++) {
 DataBean dataBean = new DataBean(Refresh.COMMON);
 dataBean.number = String.valueOf(i) + "fly";
 lists.add(dataBean);
 }
 adapter.notifyDataSetChanged();
 onHintLoadMore();
 }
}