android - 在微调器中设置键和值

Question

我有一个微调器，我想在上面设置一个键和一个值，我使用 HashMap，它可以工作，但显示一行，像这样:

代码:

        final View rootView = inflater.inflate(R.layout.fragment_photos, container, false);

    Spinner spin=(Spinner)rootView.findViewById(R.id.spinner1);

    HashMap<Integer, String> P_Hash=new HashMap<Integer, String>();

    Update Get_Information=new Update(rootView.getContext());

    ArrayList<String> Province_NAME=new ArrayList<String>();
    Province_NAME=Get_Information.GET_Province();

    ArrayList<Integer> Province_ID=new ArrayList<Integer>();
    Province_ID=Get_Information.Get_Province_ID();

    for (int i = 0; i < Province_ID.size(); i++)
    {
        P_Hash.put(Province_ID.get(i), Province_NAME.get(i));
        Log.d("Province_ID.get(i)", Province_ID.get(i)+"");
        Log.d(" Province_NAME.get(i)",  Province_NAME.get(i)+"");
    }


    ArrayAdapter<HashMap<Integer, String>> adapter = new ArrayAdapter<HashMap<Integer,String>>(rootView.getContext(), android.R.layout.simple_spinner_item);
    adapter.add(P_Hash);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spin.setAdapter(adapter);

Answer 1

用键和值填充微调器的更好方法应该是:

第 1 步:创建 POJO 类来处理键和值

public class Country {

    private String id;
    private String name;
    
    public Country(String id, String name) {
        this.id = id;
        this.name = name;
    }


    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }


    //to display object as a string in spinner
    @Override
    public String toString() {
        return name;
    }

    @Override
    public boolean equals(Object obj) {
        if(obj instanceof Country){
            Country c = (Country )obj;
            if(c.getName().equals(name) && c.getId()==id ) return true;
        }

        return false;
    }

}

注意: toString() 方法很重要，因为它负责在 spinner 中显示数据，您可以根据需要修改 toString()

第 2 步:准备要加载到微调器中的数据

 private void setData() {

        ArrayList<Country> countryList = new ArrayList<>();
        //Add countries

        countryList.add(new Country("1", "India"));
        countryList.add(new Country("2", "USA"));
        countryList.add(new Country("3", "China"));
        countryList.add(new Country("4", "UK"));

        //fill data in spinner 
        ArrayAdapter<Country> adapter = new ArrayAdapter<Country>(context, android.R.layout.simple_spinner_dropdown_item, countryList);
        spinner_country.setAdapter(adapter);
        spinner_country.setSelection(adapter.getPosition(myItem));//Optional to set the selected item.    
    }

第三步:最后在spinner的onitemselected监听器方法中获取选中项的key和value

spinner_country.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

                 Country country = (Country) parent.getSelectedItem();
                 Toast.makeText(context, "Country ID: "+country.getId()+",  Country Name : "+country.getName(), Toast.LENGTH_SHORT).show();    
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {    
            }
        });