最好用的Android省市区三级联动选择效果

[{  "name": "河北省",  "city": [   {   "name": "石家庄市",   "area": [    "长安区",    "桥东区",    "桥西区",    "新华区",    "郊 区",    "井陉矿区",    "井陉县",    "正定县",    "栾城县",    "行唐县",    "灵寿县",    "高邑县",    "深泽县",    "赞皇县",    "无极县",    "平山县",    "元氏县",    "赵 县",    "辛集市",    "藁",    "晋州市",    "新乐市",    "鹿泉市"   ]   },......] 

/**   * 从assert文件夹中获取json数据   */  private void initJsonData() {    Observable.create(new ObservableOnSubscribe<List<Province>>() {    @Override    public void subscribe(ObservableEmitter<List<Province>> emitter) throws Exception {     List<Province> provinces = new ArrayList<>();     try {      StringBuffer sb = new StringBuffer();      InputStream is = getAssets().open("citylist.json");//打开json数据      byte[] by = new byte[is.available()];//转字节      int len = -1;      while ((len = is.read(by)) != -1) {       sb.append(new String(by, 0, len, "utf8"));//根据字节长度设置编码      }      is.close();// 关闭流      // 通过Gson将字符串转成对象list      Gson gson = new Gson();      provinces = gson.fromJson(sb.toString(), new TypeToken<List<Province>>() {      }.getType());     } catch (Exception e) {      e.printStackTrace();     } finally {      emitter.onNext(provinces);     }    }   }).subscribeOn(Schedulers.io())     .observeOn(AndroidSchedulers.mainThread())     .subscribe(new Consumer<List<Province>>() {      @Override      public void accept(List<Province> provinces) throws Exception {       if (provinces != null && provinces.size() > 0) {        RegionSelectActivity.this.provinces = provinces;        // 显示数据        showData();       }      }     });  }

/**   * 展示数据   */  private void showData() {   for (Province province : provinces) {    provinceList.add(province.getName());   }   // 显示省份数据   spProvince.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, provinceList));   spProvince.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {    @Override    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {     provincePosition = position;     provinceName = provinceList.get(position);     // 获取当前省份对应的城市list     cityList.clear();     List<Province.CityBean> cityBeans = provinces.get(position).getCity();     for (Province.CityBean city : cityBeans) {      cityList.add(city.getName());     }     // 刷新城市列表     spCity.setSelection(0);     cityName = cityList.get(0);     cityAdapter.notifyDataSetChanged();      // 刷新城区列表     updateArea(0);    }     @Override    public void onNothingSelected(AdapterView<?> parent) {     }   });    // 显示城市数据   spCity.setAdapter(cityAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, cityList));   spCity.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {    @Override    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {     cityPosition = position;     cityName = cityList.get(position);     // 刷新城区列表     updateArea(position);    }     @Override    public void onNothingSelected(AdapterView<?> parent) {     }   });    // 显示城区数据   spArea.setAdapter(areaAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, areaList));   spArea.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {    @Override    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {     areaName = areaList.get(position);    }     @Override    public void onNothingSelected(AdapterView<?> parent) {     }   });