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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