如何使用 JSON 数据创建自定义微调器适配器？

Question

当我将数据从列表数据加载到微调器时，它起作用了。但是当我为微调器创建适配器时，它不起作用。我的问题是什么？

Activity:

final FieldOfficerApiInterface apiService=OperatingApiClient.getClient().create(FieldOfficerApiInterface.class);

        Call<FieldOfficerApiResponse> call = apiService.getAllEOByBranchID(branchid);
        call.enqueue(new Callback<FieldOfficerApiResponse>() {
            @Override
            public void onResponse(Call<FieldOfficerApiResponse> call, Response<FieldOfficerApiResponse> response) {
                List<FieldOfficer> fieldofficerlist=response.body().getFieldofficerlist();
                Log.d(TAG,"Number of Fieldofficerlist received: "+fieldofficerlist.size());

                //*********DROPDOWN******************************************************

                final Spinner spnrFieldOfficer=(Spinner)findViewById(R.id.spinnerFieldOfficer);

                CustomSpinnerAdapter adapter=new CustomSpinnerAdapter(getApplicationContext(),fieldofficerlist);
                spnrFieldOfficer.setAdapter(adapter);

                //*********END DROPDOWN******************************************************
            }

            @Override
            public void onFailure(Call<FieldOfficerApiResponse> call, Throwable t) {
                // Log error here since request failed
                Log.e(TAG,t.toString());

            }
        });

CustomSpinnerAdapter:

public class CustomSpinnerAdapter extends BaseAdapter {

    private List<FieldOfficer> fieldOfficers;
    private Context context;
    LayoutInflater inflter;


    public CustomSpinnerAdapter(Context context, List<FieldOfficer> fieldOfficers) {
        this.context = context;
        this.fieldOfficers = fieldOfficers;
        this.inflter = (LayoutInflater.from(context));
    }

    @Override
    public int getCount() {
        return 0;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        convertView=inflter.inflate(R.layout.custom_spinner_items,null);
        TextView tv=(TextView)convertView.findViewById(R.id.textView2);
        tv.setText(fieldOfficers.get(position).getFoname());
        return convertView;
    }
}

它在没有自定义适配器的情况下工作：

//*********DROPDOWN******************************************************
                ArrayAdapter<FieldOfficer> adapter;
                adapter = new ArrayAdapter<FieldOfficer>(getApplicationContext(), android.R.layout.simple_selectable_list_item,fieldofficerlist); //getApplication()
                //setting adapter to spinner
                spnrFieldOfficer.setAdapter(adapter);
//*********END DROPDOWN******************************************************

Answer 1

更改您的 getCount() 像这样

 @Override
    public int getCount() {
        if (fieldOfficers!= null) {
            return fieldOfficers.size();
        }
        return 0;
    }

Answer 2

微调器将调用您的 getCount() 以确定列表中有多少项，在您的实现中，您告诉它列表始终为空。

将您的 getCount() 更改为以下

@Override
    public int getCount() {
        if (fieldOfficers!= null) {
            return fieldOfficers.size();
        }
        return 0;
    }

如何使用 JSON 数据创建自定义微调器适配器？

How to create Custom spinner adapter with JSON Data?

android

spinner

custom-adapter

android-spinner

retrofit2