未为类型“_CreateEventState”定义方法“FormBuilderDateTimePicker”

如何解决未为类型“_CreateEventState”定义方法“FormBuilderDateTimePicker”

我正在尝试将 FormBuilder 用于我的项目以将事件添加到日历，我使用了 ForBuilderTextfield() 和 FormBuilderSwitch()，但是当我尝试将 FormBuilderDateTimePicker 定义为输入日期我收到以下错误：

未为该类型定义方法“FormBuilderDateTimePicker” '_CreateEventState'

我的 pubsec.yaml 包含以下软件包：

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 课：

    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,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,fontSize: 16,initialValue: false,controlAffinity: ListTileControlAffinity.leading,decoration: InputDecoration(
                    border: InputBorder.none,RichText(
                text: TextSpan(
                  text: 'Event Date',style: TextStyle(
                    color: AppColors.blue,//Add the FormBuilderDateTimePicker here
            ],]
    )
  );
}```