没网的时候共用一个适配器进行展示

创建Dao

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import java.util.ArrayList;
import java.util.List;

/**
 * <p>文件描述：<p>
 * <p>作者：JYB<p>
 * <p>创建时间：2019/1/4<p>
 * <p>更改时间：2019/1/4<p>
 * <p>版本号：1<p>
 */
public class Dao {

    private final SQLiteDatabase database;

    public Dao(Context context){
        openHelper helper = new openHelper(context);
        database = helper.getWritableDatabase();
    }
    //添加
    public long add(Bean.DataBean bean){
        ContentValues values = new ContentValues();
        values.put("news_id",bean.getNews_id());
        values.put("news_title",bean.getNews_title());
        values.put("news_summary",bean.getNews_summary());
        values.put("pic_url",bean.getPic_url());
        long insert = database.insert("user", null, values);
        return insert;

    }
    //查询
    public List<Bean.DataBean> queryAll(){
        Cursor cursor = database.query("user", null, null, null, null, null, null);
        List<Bean.DataBean> list = new ArrayList<>();
        while(cursor.moveToNext()){
            String news_id = cursor.getString(cursor.getColumnIndex("news_id"));
            String news_title = cursor.getString(cursor.getColumnIndex("news_title"));
            String news_summary = cursor.getString(cursor.getColumnIndex("news_summary"));
             String pic_url = cursor.getString(cursor.getColumnIndex("pic_url"));
             list.add(new Bean.DataBean(news_id,news_summary,news_title,pic_url));
        }
        return  list;
    }


}

创建openHelper

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

/**
 * <p>文件描述：<p>
 * <p>作者：JYB<p>
 * <p>创建时间：2019/1/4<p>
 * <p>更改时间：2019/1/4<p>
 * <p>版本号：1<p>
 */
class openHelper extends SQLiteOpenHelper {
    private static final String DB_NAME = "name.db";
    public openHelper(Context context) {
        super(context, DB_NAME, null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("create table user(id integer primary key autoincrement," +
                "news_id text," +
                "news_title text," +
                "news_summary text," +
                "pic_url text)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}

适配器里一定要使用setList

 public void setList(List<Bean.DataBean> list) {
        this.list = list;
        //刷新适配器
        notifyDataSetChanged();
    }

使用for循环添加数据

 //将数据用For循环一个一个的添加到数据库
            for(int i=0;i<data.size();i++){
                String news_id = data.get(i).getNews_id();
                String news_title = data.get(i).getNews_title();
                String news_summary = data.get(i).getNews_summary();
                String url = data.get(i).getPic_url();
                Bean.DataBean dataBean = new Bean.DataBean(news_id, news_title, news_summary, url);
                dao.add(dataBean);
            }

展示的操作

//没有网，查询数据库的信息，放到适配器
            List<Bean.DataBean> dataBeans = dao.queryAll();
            //开启数据库数据
           adapter.setList(dataBeans);