我正在用getx创建一个应用程序。我有简单的GET请求，我把数据显示在屏幕上。在详细信息屏幕上，我放了一个按钮来刷新请求，请求的响应是随机的，所以每次用户按下按钮时都会显示不同的文本。我不知道如何做到这一点。
我的控制者：

class JokeController extends GetxController {
  var isLoading = true.obs;
  var joke = Joke().obs;

  @override
  void onInit() {
    fetchJoke();
    super.onInit();
  }

  void fetchJoke() async {
    isLoading(true);
    try {
      var chosenCategory = GetStorage().read("chosenCategory");
      var _joke = await Requests.getJoke(chosenCategory);
      if (_joke != null) {
        joke.value = _joke;
      }
    } finally {
      isLoading(false);
    }
  }
}

我的请求：

static Future<Joke> getJoke(String chosenCategory) async {   
    try {
      var response =
          await client.get(Uri.parse(url)).timeout(Duration(seconds: 10));

      if (response.statusCode == 200) {
        Joke _joke = new Joke();
        var responseBody = response.body;
        return _joke.jokeFromJson(responseBody);
      }
    } catch (error) {
      return null;
    }
  }

页面中（Obx）：

Obx(() {
            if (jokeController.isLoading.value) {
              return Center(
                child: CircularProgressIndicator().reactive(),
              );
            }
            return Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Center(
                    child: Padding(
                  padding: EdgeInsets.only(
                      right: MediaQuery.of(context).size.width * .1,
                      left: MediaQuery.of(context).size.width * .1),
                  child: Text(
                    jokeController.joke.value.value,
                    textAlign: TextAlign.center,
                    style: TextStyle(
                        fontSize: MediaQuery.of(context).size.width * .06,
                        fontWeight: FontWeight.bold),
                  ),
                )),
                SizedBox(
                  height: MediaQuery.of(context).size.height * .2,
                ),
                Container(
                    alignment: Alignment.bottomCenter,
                    width: 250,
                    height: 60,
                    child: Opacity(
                        opacity: 0.88,
                        child: ElevatedButton(
                          style: ElevatedButton.styleFrom(
                              padding: EdgeInsets.zero,
                              shape: RoundedRectangleBorder(
                                  borderRadius: BorderRadius.circular(30)),
                              shadowColor: Colors.orange),
                          clipBehavior: Clip.antiAlias,
                          onPressed: () {
                            //Refresh the joke
                          },
                          child: Ink(
                            decoration: BoxDecoration(
                                gradient: LinearGradient(
                                    begin: Alignment.bottomCenter,
                                    end: Alignment.topCenter,
                                    colors: [
                                  Colors.orange,
                                  Colors.orange[200]
                                ])),
                            child: Container(
                              constraints:
                                  BoxConstraints(maxHeight: 300, minWidth: 50),
                              alignment: Alignment.center,
                              child: Text(
                                "SEE ANOTHER JOKE FROM THIS CATEGORY",
                                style: TextStyle(
                                    fontSize:
                                        MediaQuery.of(context).size.width * .03,
                                    fontWeight: FontWeight.bold),
                              ),
                            ),
                          ),
                        )))
              ],
            );
          })

到目前为止，我在onPressed下尝试了以下操作：

1. jokeController.joke.refresh();
2. setState ((){});
3. Get.to(JokePage());
   但这些都不起作用。我也从GetStorage获取类别，当用户单击上一页的类别时，我会将其获取。该类别不会更改。提前感谢。我还包括该页的图片：