如何知道何时仍在 Stream builder 中加载 post 方法

如何解决如何知道何时仍在 Stream builder 中加载 post 方法

所以我有一个表单，可以将数据发送到服务器，并且发送时我想显示循环加载。我在这里只显示接收数据时的加载，而不是发送时的加载。发送数据后，我想返回上一个屏幕。

界面 这里只显示数据发送到服务器时循环加载。

Widget build(BuildContext context) {
    return StreamBuilder(
      stream: manager.addPost,builder: (context,AsyncSnapshot<Post> snapshot) {

        debugPrint(snapshot.connectionState.toString());
          if (!snapshot.hasData) {
            return buildColumn();
          }else if (snapshot.hasError) {
            return Center(
              child: Text(
                snapshot.error.toString(),style: TextStyle(fontSize: 20),),);
          }
            return Center(child: CircularProgressIndicator());
      }
    );
  }


Widget buildColumn() =>
      Form(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.start,children: <Widget>[
              Padding(
                padding: const EdgeInsets.all(8.0),child: buildTitle(),SizedBox(
                height: 10,Padding(
                padding: const EdgeInsets.all(8.0),child: buildDesription(),buildSubmit()
            ],));



  Widget buildSubmit() => StreamBuilder<Object>(
      stream: manager.isFormValid,snapshot) {
        return ElevatedButton(onPressed: (){
          if(snapshot.hasData){
            manager.submit();
          debugPrint("YEs");

          }
        },child: Text("SEND"));
      });

提交

 Future submit() async {
    String title = _title.value;
    String description = _description.value;
    Post itemModel = await _repository.addPost(title,description);
    _postsFetcher.sink.add(itemModel);
    return itemModel;
  }

回购

final postRepo = CreatePostRepository();
Future<Post> addPost(String title,String description) => postRepo.createPost(title,description);

最后是post方法

class CreatePostRepository {
  Future<Post> createPost(String title,String description) async {
    final response = await http.post(
      Uri.parse(getPostUrl),headers: <String,String>{
        'Content-Type': 'application/json; charset=UTF-8',},body: jsonEncode(
          <String,dynamic>{"title": title,"body": description,"userId": 1}),);

    if (response.statusCode == 201) {
      print(' created 201: ');
      print(response.body.toString());
      return Post.fromJson(jsonDecode(response.body));

    } else {
      print('not throw: ');
      throw Exception('failed to add post');
    }
  }
}