所有消息时间戳在发送消息时不断更新为当前时间

Question

下面是我的代码，当我将每条消息更新的所有时间戳发送到当前时间时，我如何确保时间不会在任何旧消息上发生变化？我已经正确地提取了时间戳，只是错过了我在保存个人时间戳时做错了什么。我没有使用 firebase 时间戳，只是使用 dart 给我的 DateTime

import 'dart:ffi';
import 'package:bardsf/components/card_data.dart';
import 'package:bardsf/screens/admin/admin_chat.dart';

import 'package:bardsf/screens/main_screens/qr_screen.dart';

import 'package:bardsf/screens/workouts/workout_selector.dart';
import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:bardsf/components/reusable_cards.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
import '../chat/chat_selector_screen.dart';
import 'package:bardsf/screens/chat/chat_screen.dart';
import 'package:intl/intl.dart';


late String messageText;
class HomePageScreen extends StatefulWidget {
  static const String id = 'home_page_screen';


  @override
  _HomePageScreenState createState() => _HomePageScreenState();
}

class _HomePageScreenState extends State<HomePageScreen> {
  final messageTextController = TextEditingController();
  final _firestore = FirebaseFirestore.instance;

  final _auth = FirebaseAuth.instance;
  late User loggedInUser;

  static const TextStyle optionStyle = TextStyle(
      fontSize: 30, fontWeight: FontWeight.bold);
  @override
  void initState() {

    super.initState();
    getCurrentUser();
  }
  void getCurrentUser() async {
    try {
      final user = await _auth.currentUser;
      if (user != null) {
        loggedInUser = user;
        print(loggedInUser.email);
      }
    } catch (e) {
      print (e);
    }
  }
  void messagesStream() async {
    await for (var snapshot in _firestore.collection('messages').orderBy(
        'timestamp').snapshots()) {
      for (var message in snapshot.docs) {
        
        print(message.data().cast());
      }
    }
  }


  @override
  Widget build(BuildContext context) {
    return Container(

      child: Container(
        decoration: BoxDecoration(
            image: DecorationImage(
              image: AssetImage("images/bar1.jpg"), fit: BoxFit.fill,
            )
        ),
        child: Scaffold(
          backgroundColor: Colors.white.withOpacity(0.5),


          body: SafeArea(


            child: Column(

                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: <Widget>[
                  ReusableCard(
                    colour: Colors.white,
                    cardChild: CardData(
                      label: 'The Bar',
                      labeltwo: 'Member Access 24/7', icon: IconData(10),
                    ), onPress: () {},
                  ),
                  StreamBuilder<QuerySnapshot>(

                    stream: _firestore.collection('messages').snapshots(),
                    builder: (context, snapshot) {
                      List<MessageBubble> messageBubbles = [];
                      if (!snapshot.hasData) {
                        return Center(
                          child: CircularProgressIndicator(
                            backgroundColor: Colors.lightBlueAccent,
                          ),
                        );
                      }
                      final messages = snapshot.data!.docs;

                      for (var message in messages) {
                        final messageText = message['text'];
                        final messageSender = message['sender'];

                        final currentUser = loggedInUser.email;


                        final messageBubble = MessageBubble(
                          sender: 'The Bar Gym',
                          text: messageText,
                          isMe: currentUser == messageSender,
                          daterTimer: DateTime.now().millisecondsSinceEpoch,

                        );

                        messageBubbles.add(messageBubble);
                      }


                      return Expanded(

                        child: Padding(
                          padding: const EdgeInsets.all(40.0),
                          child: Container(
                            color: Colors.white.withOpacity(0.6),
                            child: ListView(

                              reverse: false,
                              padding: EdgeInsets.symmetric(
                                  horizontal: 10, vertical: 10),
                              children: messageBubbles,
                            ),
                          ),
                        ),
                      );
                    },


                  ),


                ]
            ),
          ),

        ),
      ),

    );
  }
}

class MessageBubble extends StatelessWidget {


  MessageBubble({required this.sender,required this.text,required this.isMe, required this.daterTimer });

  final String sender;
  final String text;
  final bool isMe;
  final int daterTimer;

  String readTimestamp(int timestamp) {
    var now = new DateTime.now();
    var format = new DateFormat('M/d' ' ' 'K:m'' ''a');
    var date = DateTime.fromMillisecondsSinceEpoch(timestamp);
    var diff = date.difference(now);
    var time = '';


    if (diff.inSeconds <= 0 || diff.inSeconds > 0 && diff.inMinutes == 0 || diff.inMinutes > 0 && diff.inHours == 0 || diff.inHours > 0 && diff.inDays == 0) {
      time = format.format(date);
    } else {
      if (diff.inDays == 1) {
        time = (diff.inDays/360).toString() + 'DAY AGO';
      } else {
        time = (diff.inDays/360).toString() + 'DAYS AGO';
      }
    }

    return time;
  }


  @override

  Widget build(BuildContext context) {
    return  Padding(
      padding: EdgeInsets.all(10.0),
      child: Column(
        crossAxisAlignment: isMe ? CrossAxisAlignment.stretch : CrossAxisAlignment.start,
        children: <Widget>[
          Row(
            children: [
              Expanded(
                child: Text(sender,
                  style: TextStyle(
                    fontSize: 12.0,
                    color: Colors.red,
                  ),
                ),
              ),
              Expanded(child: Text('${readTimestamp(daterTimer)}',
                style: TextStyle(color: Colors.black)
              ),
              ),
            ],
          ),
          Material(
            // borderRadius: isMe ? BorderRadius.only(topLeft: Radius.circular(30.0),
            //   bottomLeft: Radius.circular(30.0),
            //   bottomRight: Radius.circular(30.0),
            //   topRight: Radius.circular(30.0)
            // ) : BorderRadius.only(topRight: Radius.circular(30.0),
            //   bottomLeft: Radius.circular(30.0),
            //   bottomRight: Radius.circular(30.0),
            //   topLeft: Radius.circular(30.0),
            // ),

            elevation: 5.0,
            color: isMe ? Colors.transparent : Colors.white,
            child: Padding(
              padding: EdgeInsets.symmetric(vertical: 8.0, horizontal: 10.0),
              child: Text('$text',
                style: TextStyle( fontSize: 15.0,
                  fontWeight: FontWeight.bold,
                  color: isMe ? Colors.white : Colors.black,),
              ),

            ),
          ),

        ],
      ),
    );
  }
}

Answer 1

你的错误在这一行：

daterTimer: DateTime.now().millisecondsSinceEpoch,

您似乎覆盖了从 Firestore 读取的值。它应该是这样的：

daterTimer: message['timestamp'];,

根据您的具体情况进行调整

如果这没有帮助，请告诉我。

编辑 1：

基本上，您不是在读取 Firestore 中的时间戳，而是在读取现在的时间。

试试这个：

daterTimer: (json['timestamp'] == null) ? null : (json['timestamp'] as Timestamp).toDate(),

如果它不起作用，您需要告诉我 Firestore 中的 'timestamp' 字段是什么类型以及您用来写入 Firestore 的代码。

编辑 2：

我打错了。试试这个：

daterTimer: (message['timestamp'] == null) ? null : (message['timestamp'] as Timestamp).toDate(),

Answer 2

我不得不更改这些行，它起作用了

daterTimer: (message['timestamp'] == null) ? null : (message['timestamp'] as Timestamp).toDate(),


 final DateTime? daterTimer;



 Expanded(child: Text('${daterTimer}',

所有消息时间戳在发送消息时不断更新为当前时间

all messages time stamps keep updating to current time when a message is sent

timestamp

chat

dart

flutter