WheelView实现省市区三级联动(数据库实现版本号附带完整SQL及数据)

    近期在实现收货地址功能，用到了省市区三级联动效果，网上找到一般都是xml或json。数据源陈旧改动麻烦。改动了一下使用数据库方式实现了一下

   数据源解决。因为数据量比較大通过初始化批量运行SQL的方式不合适，费时不说还easy出错，我採用的是在电脑上创建好数据库然后把数据库文件放到程序里边，通过以下这种方法能够把db文件复制到随意文件夹下。demo中我把文件放在了raw文件夹下

/**
     *
     * @param inStream
     * @param fileNme 文件名称
     * @param newPath 要拷贝到的目录路径
     */
    public void copyFile(InputStream inStream,String fileNme, String newPath) {
        try {
            int bytesum = 0;
            int byteread = 0;

            File file = new File(newPath);
            //保证目录存在
            if (!file.exists()) {
                file.mkdir();
            }
            //假设文件存在覆盖
            File newFile=new File(newPath+File.separator+fileNme);
            if(newFile.exists()){
                newFile.delete();
                newFile.createNewFile();
            }
            FileOutputStream fs = new FileOutputStream(newFile);
            byte[] buffer = new byte[1024 * 2];
            int length;
            while ((byteread = inStream.read(buffer)) != -1) {
                bytesum += byteread; //字节数 文件大小
                System.out.println(bytesum);
                fs.write(buffer, 0, byteread);
            }
            inStream.close();
            fs.close();
        } catch (Exception e) {
            System.out.println("拷贝文件操作出错");
            e.printStackTrace();

        }
    }

有了数据库文件仅仅须要通过下面方法就能够对该数据库做操作了，该方法返回的是给定数据库的引用

/**
     * 打开数据库文件
     * @return
     */
    public SQLiteDatabase openDataBase(){
        SQLiteDatabase database = SQLiteDatabase.openOrCreateDatabase(
                DATABASES_DIR+DATABASE_NAME, null);
        return database;
    }

接下来就是查询数据源了

/**
     *
     * @param db
     * @return 查询全部的省
     */
    public List getProvice(SQLiteDatabase db){
        String sql="SELECT * FROM t_address_province ORDER BY id";
        Cursor cursor = db.rawQuery(sql,null);
        List list=new ArrayList();

        if (cursor!=null&&cursor.getCount() > 0) {
            while (cursor.moveToNext()){
                ProvinceModel provinceModel=new ProvinceModel();
                provinceModel.ID=cursor.getString(cursor.getColumnIndex("id"));
                provinceModel.NAME=cursor.getString(cursor.getColumnIndex("name"));
                provinceModel.CODE = cursor.getString(cursor.getColumnIndex("code"));
                list.add(provinceModel);
            }
        }
        return list;
    }

    /**
     * 依据省code查询全部的市
     * @param db
     * @param code
     * @return
     */
    public List getCityByParentId(SQLiteDatabase db,String code){
        String sql="SELECT * FROM t_address_city WHERE provinceCode=? ORDER BY id";
        Cursor cursor = db.rawQuery(sql,new String[]{code});
        List list=new ArrayList();

        if (cursor!=null&&cursor.getCount() > 0) {

            while (cursor.moveToNext()){
                CityModel cityModel=new CityModel();
                cityModel.ID=cursor.getString(cursor.getColumnIndex("id"));
                cityModel.NAME=cursor.getString(cursor.getColumnIndex("name"));
                cityModel.CODE = cursor.getString(cursor.getColumnIndex("code"));
                list.add(cityModel);
            }
        }
        return list;
    }

    /**
     * 依据市code查询全部的区
     * @param db
     * @param code
     * @return
     */
    public List getDistrictById(SQLiteDatabase db,String code){
        String sql="SELECT * FROM t_address_town WHERE cityCode=?

ORDER BY id "; Cursor cursor = db.rawQuery(sql,new String[]{code}); List list=new ArrayList(); if (cursor!=null&&cursor.getCount() > 0) { while (cursor.moveToNext()){ DistrictModel districtModel=new DistrictModel(); districtModel.ID=cursor.getString(cursor.getColumnIndex("id")); districtModel.NAME=cursor.getString(cursor.getColumnIndex("name")); districtModel.CODE = cursor.getString(cursor.getColumnIndex("code")); list.add(districtModel); } } return list; }

有了数据源工作就完毕了三分之二了，通过继承AbstractWheelTextAdapter实现自己的适配器以省为例

/**
 * Created by xuan on 16/1/7.
 */
public class ProvinceAdapter extends AbstractWheelTextAdapter {
    public List mList;
    private Context mContext;
    public ProvinceAdapter(Context context,List list) {
        super(context);
        mList=list;
        mContext=context;
    }

    @Override
    protected CharSequence getItemText(int index) {
        ProvinceModel provinceModel=mList.get(index);
        return provinceModel.NAME;
    }

    @Override
    public int getItemsCount() {
        return mList.size();
    }
}

再将Adapter给WheelView就能够了

附上完整版Demo及SQL

转载于:https://www.cnblogs.com/yxysuanfa/p/7202401.html