flutter - 将数据获取到appBar-Flutter

Question

我正在尝试将数据获取到Appbar的api，但是卡在await / async中
我正在尝试做的是:

getUserName(id) async {
  SharedPreferences prefs = await SharedPreferences.getInstance();

  String token;
  token = prefs.get('Token');
  String url = "https://apiurl";
  http.post(
    url,
    headers: {'authorization': 'bearer' + token},
    body: {'thread': id.toString()},
  ).then((response) {
    print("Response body: ${response.body}");
    return response.body;
  });
}

我在尝试构建时将其称为:

appBar: AppBar(
        title: Text(getUserInfo(widget.id)),    
        ....

但是我最终得到了:
future 动态的实例
我了解我应该以某种方式等待结果。但是，如果尝试尝试，则不接受等待:

await getUserInfo(widget.id);

Answer 1

首先等待您对http.post的 call

Future<String> getUserName(id) async {
  SharedPreferences prefs = await SharedPreferences.getInstance();

  String token;
  token = prefs.get('Token');
  String url = "https://apiurl";
  var response = await http.post(
    url,
    headers: {'authorization': 'bearer' + token},
    body: {'thread': id.toString()},
  );

  return response.body
}

然后可以使用这样的东西

// Declare _userInfo at state class level and run this on build or initState
if (_userInfo == null) {
  getUserInfo(id).then((userInfo) => setState(() => _userInfo = userInfo));
}

然后

appBar: AppBar(
    title: Text(_userInfo),