获取“InternalLinkedHashMap”不是“FutureOr”类型的子类型

Question

我是Dart/Flutter的新手，我正在努力获得一个消耗网络服务的未来的结果：

 Future<Map> _readData() async {
   (...)


http.Response response = await http.post(
    request,
    headers: {
      "SOAPAction": "http://www.totvs.com/IwsConsultaSQL/RealizarConsultaSQL",
      "Content-Type": "text/xml;charset=UTF-8",
      "Authorization": "Basic bWVzdHJlOnRvdHZz",
      "cache-control": "no-cache"
    },
    body: utf8.encode(requestBody),
    encoding: Encoding.getByName("UTF-8")
).then((onValue){

  (...)


  var dataFinal = jsonDecode(jsondataFinal);

  return  dataFinal ;
});

在init状态下，我调用此函数，因此我可以使用此结果构建布局：

     @override
  void initState () {
    super.initState();
    _readData().then((data){
      setState(() {
        print(data);

      });

    });

  }

我总是得到这个例外：

_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'FutureOr<Response>'

你知道我做错了什么吗？

谢啦

Answer 1

你不能同时使用等待和等待。你的代码应该像下面这样

Future<Map> _readData() async {
(...)

http.Response response = await http.post(
    request,
    headers: {
      "SOAPAction": "http://www.totvs.com/IwsConsultaSQL/RealizarConsultaSQL",
      "Content-Type": "text/xml;charset=UTF-8",
      "Authorization": "Basic bWVzdHJlOnRvdHZz",
      "cache-control": "no-cache"
    },
    body: utf8.encode(requestBody),
    encoding: Encoding.getByName("UTF-8")
);

  var dataFinal = jsonDecode(response.body);

  return  dataFinal ;
}

Answer 2

此错误是否与此代码一起出现？

Future<Map> _readData() async {
  //...
  http.Response response = await http.post(
    request,
    headers: {
      "SOAPAction": "http://www.totvs.com/IwsConsultaSQL/RealizarConsultaSQL",
      "Content-Type": "text/xml;charset=UTF-8",
      "Authorization": "Basic bWVzdHJlOnRvdHZz",
      "cache-control": "no-cache"
    },
    body: utf8.encode(requestBody),
    encoding: Encoding.getByName("UTF-8")
  );
  //...
  var dataFinal = jsonDecode(jsondataFinal);
  return  dataFinal ;
}