java - 回调方法响应后无法获取整数值

Question

我有一个方法可以进行 api 调用并解析响应。我在 onResponse 方法中获取当前天气的整数值。我想将此值设置为 textview 但在 onResponse 方法之后值不保留。我也将该变量设置为全局变量。这个类扩展了 fragment ，所以我在 onViewCreated 方法中设置值。

这是带有日志的方法的代码...

public class HomeScreen extends Fragment{
int currentWeather = 0;

onViewCreated(){
 curWeather = ... initialisation.
 curWeather.setText(""+getCurrentWeather);
}

public int getCurrentWeather(){

    OkHttpClient okHttpClient = new OkHttpClient();
    Request re = new Request.Builder().url(forecastURL).build();
    Call call = okHttpClient.newCall(re);
    call.enqueue(new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {

        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            String jsonResponse = response.body().string();
            JSONObject forecast;
            JSONObject currently;
            try {
                forecast = new JSONObject(jsonResponse);
                currently = forecast.getJSONObject("currently");
                currentTempFaron = (int) Math.round(currently.getDouble("temperature"));
                currentTempCelc = (currentTempFaron - 32) * 5 / 9;

                Log.d("weather in try", "" + currentTempCelc); // has weather value
            } catch (JSONException e) {
                e.printStackTrace();
            }
            Log.d("weather in response", "" + currentTempCelc); // again has weather value.
        }
    });
return currentTempCelc; //nothing it has at this point after coming out of response.
}

}

Answer 1

在 onResponse() 内执行此操作之后Log.d("weather in response", "" + currentTempCelc); :

getActivity().runOnUiThread(new Runnable() {
    @Override
    public void run() {
        curWeather.setText(Integer.toString(currentTempCelc));
    }
});

这里的问题是您试图从后台线程更新 UI 线程，这是不允许的。您可以使用runOnUiThread但出于这个目的。