Question

我正在使用Android Studio我需要从API http://mindicador.cl/api检索所有数据，我需要获取四个对象：“uf”，“dolar”，“euro”和“utm”。实际上我已经可以检索它，当我想将它添加到数组时问题就出现了，因为将来我想处理这个数组以便在RecyclerView上显示它们。

public class MainActivity extends AppCompatActivity {

    private List<IEconomicoObject> iEconomicoObjects;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        iEconomicoObjects = new ArrayList<>();

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(MiIndicadorAPI.BASE_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        MiIndicadorAPI api = retrofit.create(MiIndicadorAPI.class);

        final Call<IEconomicoAPI> iEconomicoAPICall = api.getAPI();
        iEconomicoAPICall.enqueue(new Callback<IEconomicoAPI>() {
            @Override
            public void onResponse(Call<IEconomicoAPI> call, Response<IEconomicoAPI> response) {
                iEconomicoObjects.add(response.body().getUf());
                iEconomicoObjects.add(response.body().getUtm());
                iEconomicoObjects.add(response.body().getEuro());
                iEconomicoObjects.add(response.body().getDolar());
            }

            @Override
            public void onFailure(Call<IEconomicoAPI> call, Throwable t) {
                Log.e("onFailure", "" + t.getMessage());
            }
        });

        // here is the problem, the list is empty and should be show the data added it previously
        if (!iEconomicoObjects.isEmpty()) {
            for (IEconomicoObject o: iEconomicoObjects) {
                Log.e("info", "nombre: " + o.getNombre());
            }
        } else {
            Log.e("info", "the list is empty");
        }
    }
}

Answer 1

列表在您尝试阅读时将显示为空。由于改进返回会导致与UIThread并行调用的回调，因此您应该在回调内读取列表。

将JSON对象添加到Retrofit调用函数内的数组中

1 个答案: