android - 如何在 OnResponse 函数之外使用 Retrofit 响应？

Question

我想获取改造响应列表并在 OnResponse 函数之外使用它，但是当我尝试这样做时，我总是得到一个空对象。这是我的源代码

ApiInterface apiService = ApiClient.getClient().create(ApiInterface.class);

    Call<ActivitiesResponse> call = apiService.getUserActivities(id);
    call.enqueue(new Callback<ActivitiesResponse>() {
        // If success
        @Override
        public void onResponse(Call<ActivitiesResponse>call, Response<ActivitiesResponse> response) {

             list = response.body().getActivities();// I'm getting a not null response 

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

        }
    });

    //When I try to use the list here I'm getting a null object

Answer 1

请求是异步的，因此当您尝试返回值时，请求可能尚未完成，因此您无法在请求之外使用它。如果您想从请求返回值，请使用回调接口(interface)。

将代码更改为方法并传递回调参数

示例

public void doRequest(final ApiCallback callback) {
    ApiInterface apiService = ApiClient.getClient().create(ApiInterface.class);

    Call<ActivitiesResponse> call = apiService.getUserActivities(id);
    call.enqueue(new Callback<ActivitiesResponse>() {
        // If success
        @Override
        public void onResponse(Call<ActivitiesResponse>call, Response<ActivitiesResponse> response) {

             list = response.body().getActivities();
             callback.onSuccess(list); // pass the list
        }
        // If failed
        @Override
        public void onFailure(Call<ActivitiesResponse>call, Throwable t) {
            // Log error here since request failed
            Log.e(TAG, t.toString());
        }
    });
}

public interface ApiCallback{
    void onSuccess(ArrayList<YOURTYPE> result);
}

onResume() 中的用法示例，基本上你可以在任何你想要的地方执行此操作:

public void onResume(){
    super.onResume();
    doRequest(new ApiCallback(){
         @Override
         public void onSuccess(ArrayList<YOURTYPE> result){
             //do stuff here with the list from the request
         }
    });
}

请告诉我这是否符合您的需求