flutter - 没有为类型“_CreateEventState”定义方法“FormBuilderDateTimePicker”

Question

我正在尝试将FormBuilder项目用于将事件添加到日历中，我使用了ForBuilderTextfield()and FormBuilderSwitch()，但是当我尝试定义FormBuilderDateTimePicker输入日期时，出现以下错误：

没有为类型“_CreateEventState”定义方法“FormBuilderDateTimePicker”

我的pubsec.yaml包括这些包：

environment:
  sdk: ">=2.7.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter

  cupertino_icons: ^1.0.0
  firebase_core: ^1.0.0
  google_sign_in: ^4.5.9
  provider: ^4.3.3
  firebase_auth: ^1.0.1
  flutter_signin_button: ^1.1.0
  google_fonts: ^2.0.0
  flutter_bloc: ^3.2.0
  flutter_secure_storage: ^3.3.5
  googleapis: ^1.0.0
  googleapis_auth: ^1.1.0
  path_provider: ^2.0.1
  file_picker: ^3.0.0
  url_launcher: ^6.0.2
  intl: any
  table_calendar: ^2.3.3
  firebase_storage: ^8.0.3
  flutter_form_builder: any

dependency_overrides:
  intl: ^0.17.0-nullsafety.2
  flutter_form_builder: ^6.0.0-nullsafety.1

我的_CreateEventState班级：

    class _CreateEventState extends State<CreateEvent> {

  final  _formKey = GlobalKey<FormBuilderState>();

@override
Widget build(BuildContext context) {
  return Scaffold(
      appBar: AppBar(
        title: Text('Add an Event',
          style: GoogleFonts.openSans(
            fontWeight: FontWeight.bold,
            fontStyle: FontStyle.italic,
            fontSize: 25,
            color: AppColors.royalBlue,
          ),
        ),
        backgroundColor: Colors.white,
        //Change the color of the back button to make it visible to the user.
        iconTheme: IconThemeData(
          color: AppColors.royalBlue,
        ),
      ),
    body: ListView(
      padding: const EdgeInsets.all(16.0),
      children: <Widget>[
      FormBuilder(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.start,
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              //The text above the title field - styling
              RichText(
                  text: TextSpan(
                    text: 'Event Title',
                    style: TextStyle(
                      color: AppColors.blue,
                      fontFamily: 'Raleway',
                      fontSize: 18,
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                ),
              SizedBox(height: 7.0),
              FormBuilderTextField(
                  name: "EventTitle",
                  cursorColor: AppColors.lightBlue,
                  style: TextStyle(
                    color: AppColors.royalBlue,
                    fontWeight: FontWeight.bold,
                  ),
                  decoration: InputDecoration(
                    contentPadding: EdgeInsets.only(
                      left: 15,
                      bottom: 13,
                      top: 13,
                      right: 13,
                    ),
                    hintText: 'eg: HR meeting',
                  ),
                ),
              SizedBox(height: 16.0),
              FormBuilderSwitch(
                  name: "PublicEvent",
                  title: RichText(
                    text: TextSpan(
                      text: 'Public Event',
                      style: TextStyle(
                       color: AppColors.blue,
                       fontFamily: 'Raleway',
                       fontSize: 16,
                       fontWeight: FontWeight.bold,
                       fontStyle: FontStyle.italic,
                    ),
                  ),
                      ),
                  initialValue: false,
                  controlAffinity: ListTileControlAffinity.leading,
                  decoration: InputDecoration(
                    border: InputBorder.none,
                  ),
              ),
              SizedBox(height: 7.0),
              RichText(
                text: TextSpan(
                  text: 'Event Date',
                  style: TextStyle(
                    color: AppColors.blue,
                    fontFamily: 'Raleway',
                    fontSize: 18,
                    fontWeight: FontWeight.bold,
                  ),
                ),
              ),
              SizedBox(height: 7.0),
              //Add the FormBuilderDateTimePicker here
            ],
        ),
      ),
      ]
    )
  );
}```