<android>一个老控件Spnner解决一个bug的经历（三级联动）

一个三级联动的问题，需求原型图上是一个spnner效果，本来想用pop+listview的，但是手一哆嗦就写了三个spnner，然后就用spnner做了，后台哥们想给我传json数据把城市信息给我呢，由于数据太多，我就直接用Navicat 数据库管理将php给的.sql数据库文件转成了.db格式的，然后导入assets文件夹里，下面开始解析出来数据库的各种子id，父id，城市名，不多说了，上代码吧：

/** * 城市数据库读取 */private void cityDao() {    //数据库操作    //打开数据库输出流    SQLdm s = new SQLdm();    SQLiteDatabase db = s.openDatabase(getApplicationContext());    //找到每个省   然后根据area_parent_id找到每个省对应的市    //把市添加到省集合中   再找到每个市 根据area_parent_id找到每个市对应的区    //把区添加到市集合中    //省集合    province_list = new ArrayList<>();    //找到每个省    Cursor cursor = db.rawQuery("select * from pst_area where area_deep=?", new String[]{"1"});    while (cursor.moveToNext()) {        String area_id1 = cursor.getString(cursor.getColumnIndex("area_id")); //省id        String name1 = cursor.getString(cursor.getColumnIndex("area_name"));        String area_parent_id1 = cursor.getString(cursor.getColumnIndex("area_parent_id")); //父id  此处没有        String area_deep1 = cursor.getString(cursor.getColumnIndex("area_deep")); //一级        city_list = new ArrayList<>();        //找到每个省对应的市   当area_parent_id==area_id 条件查询        Cursor cursorr = db.rawQuery("select * from pst_area where area_parent_id=?", new String[]{area_id1});        while (cursorr.moveToNext()) {            String area_id2 = cursorr.getString(cursorr.getColumnIndex("area_id")); //市id            String name2 = cursorr.getString(cursorr.getColumnIndex("area_name"));            String area_parent_id2 = cursorr.getString(cursorr.getColumnIndex("area_parent_id")); //父id  此处没有            String area_deep2 = cursorr.getString(cursorr.getColumnIndex("area_deep")); //二级            district_list = new ArrayList<>();            //找到每个省对应的区   当area_parent_id==area_id 条件查询            Cursor cursorrq = db.rawQuery("select * from pst_area where area_parent_id=?", new String[]{area_id2});            while (cursorrq.moveToNext()) {                String area_id3 = cursorrq.getString(cursorrq.getColumnIndex("area_id")); //区id                String name3 = cursorrq.getString(cursorrq.getColumnIndex("area_name"));                String area_parent_id3 = cursorrq.getString(cursorrq.getColumnIndex("area_parent_id")); //父id  此处没有                String area_deep3 = cursorrq.getString(cursorrq.getColumnIndex("area_deep")); //三级                //添加至区集合                District district = new District(); //区对象                district.setArea_id(area_id3);                district.setArea_name(name3);                district.setArea_deep(area_deep3);                district.setArea_parent_id(area_parent_id3);                district_list.add(district);            }            //添加至市集合            City city = new City();  //市对象            city.setDistricts(district_list);            city.setArea_id(area_id2);            city.setArea_name(name2);            city.setArea_deep(area_deep2);            city.setArea_parent_id(area_parent_id2);            city_list.add(city);        }        //添加至省集合        Province province = new Province(); //省对象        province.setCitys(city_list);        province.setArea_id(area_id1);        province.setArea_name(name1);        province.setArea_deep(area_deep1);        province.setArea_parent_id(area_parent_id1);        province_list.add(province);    }    //将集合用sp保存起来    address_sp.setDataList("address_tag", province_list);

这种古老的查询方法确实很锻炼人，保存起来后，紧接着设置设配器和监听：

private void init(int Province_id,int City_id,int Districte_id) {    arrayAdapter1 = new ArrayAdapter<Province>(AddAddressActivity.this, R.layout.support_simple_spinner_dropdown_item, province_list);    arrayAdapter2 = new ArrayAdapter<City>(AddAddressActivity.this, R.layout.support_simple_spinner_dropdown_item, province_list.get(Province_id).getCitys());    arrayAdapter3 = new ArrayAdapter<District>(AddAddressActivity.this, R.layout.support_simple_spinner_dropdown_item, province_list.get(Province_id).getCitys().get(City_id).getDistricts());    province_sn.setAdapter(arrayAdapter1);    city_sn.setAdapter(arrayAdapter2);    county_sn.setAdapter(arrayAdapter3);    province_sn.setSelection(Province_id, true);    city_sn.setSelection(City_id, true);    county_sn.setSelection(Districte_id, true);    //省    province_sn.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {        @Override        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {                        AddAddressActivity.this.province = province_list.get(position);            arrayAdapter2 = new ArrayAdapter<City>(AddAddressActivity.this, R.layout.support_simple_spinner_dropdown_item, province_list.get(position).getCitys());            city_sn.setAdapter(arrayAdapter2);            province_postion = position;            province_area_name_select = province_list.get(position).getArea_name();            province_area_id_select = province_list.get(position).getArea_id();                 }        @Override        public void onNothingSelected(AdapterView<?> parent) {        }    });    //市    city_sn.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {        @Override        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {            arrayAdapter3 = new ArrayAdapter<District>(AddAddressActivity.this, R.layout.support_simple_spinner_dropdown_item, AddAddressActivity.this.province.getCitys().get(position).getDistricts());            county_sn.setAdapter(arrayAdapter3);            city_postion = position;            city_area_name_select = province_list.get(province_postion).getCitys().get(position).getArea_name();            city_area_id_select = province_list.get(province_postion).getCitys().get(position).getArea_id();        }        @Override        public void onNothingSelected(AdapterView<?> parent) {        }    });    //区    county_sn.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {        @Override        public void onItemSelected(AdapterView<?> adapterView, View view, int position, long l) {            county_postion = position;            county_area_name_select = province_list.get(province_postion).getCitys().get(city_postion).getDistricts().get(position).getArea_name();            county_area_id_select = province_list.get(province_postion).getCitys().get(city_postion).getDistricts().get(position).getArea_id();                 }        @Override        public void onNothingSelected(AdapterView<?> adapterView) {        }    });}

我在想这个spnner不能直接将文字设置上去，而是要通过索引，也就是province_sn.setSelection(1, true);方法给设置上去，所以设置上去之前就必须给它先设置好数据源，那么我就开始想办法，既然集合已经保存了，后台也会返回回显的城市名字，我就直接在集合里遍历循环开始找对应的key吧，代码走着：

/** * 回显地址信息 * * @param province_id * @param city_id * @param country_id */private void showLocation(String province_id, String city_id, String country_id) {    for (int i = 0; i < province_list.size(); i++) {        if (province_id.equals(province_list.get(i).getArea_id())) {            province_sn.setSelection(i, true);            for (int j = 0; j < province_list.get(i).getCitys().size(); j++) {                if (city_id.equals(province_list.get(i).getCitys().get(j).getArea_id())) {                    city_sn.setSelection(j, true);                    for (int k = 0; k < province_list.get(i).getCitys().get(j).getDistricts().size(); k++) {                        if (country_id.equals(province_list.get(i).getCitys().get(j).getDistricts().get(k).getArea_id())) {                            county_sn.setSelection(k, true);                        }                    }                }            }        }    }}

当时写完这段，感觉做为一个前端好累啊，还要这么查，运行后发现这段代码并什么卵用，根本定位不到，果断就找后台去了，让后台哥们给我加了三个城市分别对应的选中的索引值字段，新字段来了，操练起来了，结果设置各种后发现只有省级是可以定位到的，市级，区级只是数据显示了，却索引位始终是0位置，并没有定位到，当时的代码：

arrayAdapter1 = new ArrayAdapter<Province>(AddAddressActivity.this, R.layout.support_simple_spinner_dropdown_item, province_list);arrayAdapter2 = new ArrayAdapter<City>(AddAddressActivity.this, R.layout.support_simple_spinner_dropdown_item, province_list.get(Province_id).getCitys());arrayAdapter3 = new ArrayAdapter<District>(AddAddressActivity.this, R.layout.support_simple_spinner_dropdown_item, province_list.get(Province_id).getCitys().get(City_id).getDistricts());province_sn.setAdapter(arrayAdapter1);city_sn.setAdapter(arrayAdapter2);county_sn.setAdapter(arrayAdapter3);province_sn.setSelection(Province_id, true);city_sn.setSelection(City_id, true);county_sn.setSelection(Districte_id, true);

左思右想代码，没问题，肯定可以的啊，项目也很紧张，各种资料翻spnner的属性和特点，查到一篇帖子是这样说的，setSelection(Province_id,true);二参如果为ture的话，会自动刷新，而且会重新走一遍

setOnItemSelectedListener监听，这时我一看setOnItemSelectedListener下的代码：

//省province_sn.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {    @Override    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {                AddAddressActivity.this.province = province_list.get(position);        arrayAdapter2 = new ArrayAdapter<City>(AddAddressActivity.this, R.layout.support_simple_spinner_dropdown_item, province_list.get(position).getCitys());        city_sn.setAdapter(arrayAdapter2);        province_postion = position;       province_area_name_select = province_list.get(position).getArea_name();      }
里面竟然又走了一遍设置市级的数据，这下就有谱了，本来是定位到的，结果市级区级又重新设置了一遍适配器，所以给人感觉就是没定位到。
后来解决办法也很简单，在onItemSelected方法里直接加了个判断，如果是回显的情况下就直接返回：
if (address_id != null) {    return;}

问题解决，怪自己对控件的属性了解不彻底，但是财富值+1，那是没得说的。希望对大家有帮助。