android中RecyclerView的简单使用（四）——上下拉刷新的实现

上一篇讲述了recyclerview实现瀑布流，而在本篇中将讲述recycler view实现上下拉刷新。（附加嵌套checkbox错乱问题的解决）

代码中添加了较为详细的注释，就不多说了，直接贴代码。

代码如下：

首先，先贴出Adapter中的代码。

package com.example.cn.bgs.swiprecycleviewdemo;

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

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerView.ViewHolder;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MyAdapter extends RecyclerView.Adapter<ViewHolder> {
private Context context;
private List<String> list;
// 加载的状态
private int loadState = LOADING;
// 两种view的类型
private static final int ITEM_VIEW = 1;
private static final int FOOTER_VIEW = 2;
// 底部视图的两种方式-加载更多 和 没有更多数据了
private static final int LOADING = 3;
private static final int NO_MORE = 4;
private boolean isChecked;

private Map<Integer,Boolean> map=new HashMap<Integer,Boolean>();

public MyAdapter(Context context, List<String> list) {
this.context = context;
this.list = list;
}
/*
* 获得相应位置视图的类型
*/

@Override
public int getItemViewType(int position) {
// TODO Auto-generated method stub
if (position + 1 == getItemCount()) {
//底部视图
return FOOTER_VIEW;
} else {
//条目试图
return ITEM_VIEW;
}

}
/*
* 设置适配器加载的状态（加载更多和没有更多）
*/

public void setloadState(int state) {
this.loadState = state;
notifyDataSetChanged();
}

@Override
public int getItemCount() {
// TODO Auto-generated method stub
return list.size() + 1;
}

@Override
public void onBindViewHolder(ViewHolder holder, final int pos) {
// TODO Auto-generated method stub
if (holder instanceof ItemHolder) {
((ItemHolder) holder).mtv.setText(list.get(pos));
final Integer tag=new Integer(pos);
((ItemHolder) holder).mcb.setTag(tag);
if(map.containsKey(tag)){
((ItemHolder) holder).mcb.setChecked(map.get(tag));
}else{
((ItemHolder) holder).mcb.setChecked(false);
}
((ItemHolder) holder).mcb.setOnCheckedChangeListener(new OnCheckedChangeListener() {

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// TODO Auto-generated method stub
if(!isChecked){
map.put(tag, true);
}else{
map.put(tag, false);
}
}
});

}
if (holder instanceof FooterHolder) {
//判断底部视图加载状态
switch (loadState) {
case LOADING:
((FooterHolder) holder).mpb.setVisibility(View.VISIBLE);
((FooterHolder) holder).mtv.setText("正在加载更多数据...");
break;
case NO_MORE:
((FooterHolder) holder).mpb.setVisibility(View.GONE);
((FooterHolder) holder).mtv.setText("没有更多数据了...");
break;
}
}
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// TODO Auto-generated method stub
//根据viewHolder判断布局的加载
switch (viewType) {
case ITEM_VIEW:
View v = LayoutInflater.from(context).inflate(R.layout.item,
parent, false);
ItemHolder holder = new ItemHolder(v);
return holder;

case FOOTER_VIEW:
View fv = LayoutInflater.from(context).inflate(R.layout.footer,
parent, false);
FooterHolder fholder = new FooterHolder(fv);
return fholder;
}
return null;

}

}

class ItemHolder extends ViewHolder {
public TextView mtv;
public CheckBox mcb;

public ItemHolder(View v) {
super(v);
// TODO Auto-generated constructor stub
mtv = (TextView) v.findViewById(R.id.mtv);
mcb=(CheckBox) v.findViewById(R.id.mcb);
}

}

class FooterHolder extends ViewHolder {
public ProgressBar mpb;
public TextView mtv;

public FooterHolder(View v) {
super(v);
// TODO Auto-generated constructor stub
mpb = (ProgressBar) v.findViewById(R.id.mpb);
mtv = (TextView) v.findViewById(R.id.mtv);
}

}

然后就是MainActivity中的代码：

package com.example.cn.bgs.swiprecycleviewdemo;

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

import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v4.widget.SwipeRefreshLayout.OnRefreshListener;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerView.OnScrollListener;
import android.view.Menu;

public class MainActivity extends Activity {
private RecyclerView mrv;
private SwipeRefreshLayout mswip;
private MyAdapter adapter;
//判断是否加载数据
private boolean isLoading;
//当前页面能见的最后一个item的id
private int lastId;
private int state;
private LinearLayoutManager linearManager;
//能显示的数据最大值
private int maxSize = 48;
//底部视图的两种状态
private static final int LOADING = 3;
private static final int NO_MORE = 4;
private List<String> list = new ArrayList<String>();

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mrv = (RecyclerView) findViewById(R.id.mrv);
linearManager = new LinearLayoutManager(this);
mswip = (SwipeRefreshLayout) findViewById(R.id.mswip);
list = new ArrayList<String>();

for (int i = 0; i < 20; i++) {
list.add("item" + i);
}
adapter = new MyAdapter(this, list);
mrv.setAdapter(adapter);
mrv.setLayoutManager(linearManager);
mswip.setColorSchemeResources(R.color.color1, R.color.color2,
R.color.color3, R.color.color4);
//下拉刷新的监听
mswip.setOnRefreshListener(new OnRefreshListener() {

@Override
public void onRefresh() {
// TODO Auto-generated method stub
new Handler().postDelayed(new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub
for (int i = 5; i > 0; i--) {
list.add(0, "new item" + i);

}
adapter.notifyDataSetChanged();
mswip.setRefreshing(false);
}
}, 3000);
}
});
//上拉加载的监听
mrv.setOnScrollListener(new OnScrollListener() {

@Override
public void onScrolled(int arg0, int arg1) {
// TODO Auto-generated method stub
//mrv滑动的时候会回调这个方法
lastId = linearManager.findLastVisibleItemPosition();
}

@Override
public void onScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
//判断是否是最后一条
if (lastId + 1 == adapter.getItemCount()
&& state == RecyclerView.SCROLL_STATE_IDLE
&& !isLoading) {
isLoading = true;
final int count = adapter.getItemCount();
new Handler().postDelayed(new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub
//判断是否加载到最大值了
if (count + 10 < maxSize) {
for (int i = count; i < count + 10; i++) {
list.add("load more" + i);
}
adapter.notifyDataSetChanged();
} else {
for (int i = count; i < maxSize; i++) {
list.add("load more" + i);
}
adapter.setloadState(NO_MORE);

4000
}
isLoading = false;
}
}, 3000);
}
}
});
}

}

以上四篇文章就是我对recycler v iew的了解，如有不足或者欠缺的地方，还望多多指教。