名称“文件”在库“dart:html”和“dart:io”中定义

有谁知道如何解决这个错误，这是我的代码，导入错误在“文件”中，错误如下：

名称“文件”在库“dart:html”和“dart:io”中定义。

@override
State createState() => ChatScreenState(receiverId: receiverId, receiverAvatar: receiverAvatar);
}
class ChatScreenState extends State
{
final String receiverId;
final String receiverAvatar;
ChatScreenState({
Key key,
@required this.receiverId,
@required this.receiverAvatar,
});
final TextEditingController textEditingCOntroller= TextEditingController();
final ScrollController listScrollCOntroller= ScrollController();
final FocusNode focusNode = FocusNode();
bool isDisplaySticker;
bool isLoading;
File imageFile;
String imageUrl;
String chatId;
SharedPreferences preferences;
String id;
var listMessage;
@override
void initState() {
// TODO: implement initState
super.initState();
focusNode.addListener(onFocusChange);
isDisplaySticker = false;
isLoading = false;
chatId = "";
readLocal();
}


我也导入了这个

import 'dart:async';
import 'dart:html';
import 'dart:io';
import 'package:file/file.dart';
import 'package:cached_network_image/cached_network_image.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:flutter/material.dart';
import 'package:telegramchatapp/Widgets/FullImageWidget.dart';
import 'package:telegramchatapp/Widgets/ProgressWidget.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:image_picker/image_picker.dart';
import 'package:intl/intl.dart';
import 'package:shared_preferences/shared_preferences.dart';


导入

代码的主要示例