将 File 与 ImagePicker Flutter 一起使用时出错

错误在于这一行： File selectedImage

我只导入了 dart.io，甚至没有导入 dart.html，所以我不确定为什么会出现此错误。

这是较长的一段代码

import 'dart:io';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:random_string/random_string.dart';
import 'package:tennis_event_app/services/crud.dart';

class CreateBlog extends StatefulWidget {
  @override
  _CreateBlogState createState() => _CreateBlogState();
}

class _CreateBlogState extends State<CreateBlog> {
  late String pass, authorName, title, desc;

  File selectedImage;
  final picker = ImagePicker();

  bool _isLoading = false;

  CrudMethods crudMethods = new CrudMethods();

  Future getImage() async {
    final pickedFile = await picker.getImage(source: ImageSource.gallery);

    setState(() {
      if (pickedFile != null) {
        selectedImage = File(pickedFile.path);
      } else {
        print('No image selected.');
      }
    });
  }

（这不是整个代码，只是一个更大的部分）