如何在微调器中实现微调器？

Question

假设我必须上课：

区和分区的级别

public class District {
   private int districtId;
    private String districtName;
public District(){ 
 }


    public int getDistrictId() {
        return districtId;
    }

    public String getDistrictName() {
        return districtName;
    }

    public void setDistrictId(int districtId) {
        this.districtId = districtId;
    }

    public void setDistrictName(String districtName) {
        this.districtName = districtName;
    }

    @Override
    public String toString() {
        return this.districtName;
    }
}

和SubDistric类

public class SubDistrict extends District{
    private String SubDistrictName;
    private  int SubDistrictId;
    public SubDistrict(){

    }

    public String getSubDistrictName() {
        return SubDistrictName;
    }

    public void setSubDistrictName(String subDistrictName) {
        SubDistrictName = subDistrictName;
    }

    public int getSubDistrictId() {
        return SubDistrictId;
    }

    public void setSubDistrictId(int subDistrictId) {
        SubDistrictId = subDistrictId;
    }

    @Override
    public String toString() {
        return this.SubDistrictName;
    }
}

我在activity_main.xml中有两个微调器

<Spinner
        android:id="@+id/district"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
    <Spinner
        android:id="@+id/sub_district"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/dynamic_spinner"
        />

当我选择地区时，我想过滤该地区下的子地区并在sub_district微调框中显示

我已经创建了区域适配器

public class DistrictAdapter extends BaseAdapter {
    private Context context;
    private ArrayList<District> districts;
    private ArrayList<District> originalList;

    public DistrictAdapter(Context context, ArrayList<District> districts) {
        this.context = context;
        this.districts = new ArrayList<District>();
        this.districts.addAll(districts);
        this.originalList = new ArrayList<District>();
        this.originalList.addAll(districts);
    }

    public ArrayList<District> getOriginalList() {

        return originalList;
    }

    public void setOriginalList(ArrayList<District> originalList) {
        this.originalList = originalList;
    }

    @Override
    public int getCount() {
        return districts.size();
    }

    @Override
    public Object getItem(int position) {
        return districts.get(position);
    }


    @Override
    public long getItemId(int position) {
        District district=districts.get(position);
        return district.getDistrictId();
    }



    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {

        District district=(District) getItem(i);
        if(view==null){
            LayoutInflater layoutInflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view=layoutInflater.inflate(R.layout.district_layout,null);
        }
        TextView parentText=(TextView)view.findViewById(R.id.hederTextViewId);
        parentText.setText(district.getDistrictName().trim());
        return view;
    }

    public void filterData(String query){
        query=query.toLowerCase();
        districts.clear();

        if(query.isEmpty()){
            districts.addAll(originalList);
        }
        else{
            for(District district : originalList){
                if(district.getDistrictName().toLowerCase().contains(query)){
                    districts.add(district);
                }

            }
        }
        notifyDataSetChanged();

    }
}

并且子区域适配器是

public class SubDistrictAdapter extends BaseAdapter {
    private Context context;
    private ArrayList<SubDistrict> subDistricts;
    private ArrayList<SubDistrict> originalList;

    public SubDistrictAdapter(Context context, ArrayList<SubDistrict> subDistricts) {
        this.context = context;
        this.subDistricts = new ArrayList<SubDistrict>();
        this.subDistricts.addAll(subDistricts);
        this.originalList = new ArrayList<SubDistrict>();
        this.originalList.addAll(subDistricts);
    }

    public ArrayList<SubDistrict> getOriginalList() {

        return originalList;
    }

    public void setOriginalList(ArrayList<SubDistrict> originalList) {
        this.originalList = originalList;
    }

    @Override
    public int getCount() {
        return subDistricts.size();
    }

    @Override
    public Object getItem(int position) {
        return subDistricts.get(position);
    }


    @Override
    public long getItemId(int position) {
        SubDistrict sub=subDistricts.get(position);
        return sub.getSubDistrictId();
    }


    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {

        SubDistrict sub=(SubDistrict) getItem(i);
        if(view==null){
            LayoutInflater layoutInflater=(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view=layoutInflater.inflate(R.layout.district_layout,null);
        }
        TextView parentText=(TextView)view.findViewById(R.id.hederTextViewId);
        parentText.setText(sub.getSubDistrictName().trim());
        return view;
    }

    public void filterData(String query){
        query=query.toLowerCase();
        subDistricts.clear();

        if(query.isEmpty()){
            subDistricts.addAll(originalList);
        }
        else{
            for(SubDistrict sub : originalList){
                if(sub.getSubDistrictName().toLowerCase().contains(query)){
                    subDistricts.add(sub);
                }

            }
        }
        notifyDataSetChanged();

    }
}

在Main Activity.java

中

 ArrayList<District> districts= new ArrayList<District>();

 ArrayList<SubDistrict> subDistricts=new ArrayList<SubDistrict>();

Spinner district_spinner= (Spinner) findViewById(R.id.district);

Spinner subDistrictSpinner=(Spinner)findViewById(R.id.sub_district);

DistrictAdapter     district_adapter=new DistrictAdapter(MainActivity.this,districts); 

district_spinner.setAdapter(district_adapter);

SubDistrictAdapter subDistrictAdapter=new SubDistrictAdapter(MainActivity.this,subDistricts);

subDistrictSpinner.setAdapter(subDistrictAdapter);

现在我的问题是：

1。如何获得所选地区下的分区？

2。如何在两个微调器中都实现搜索？