我正在尝试构建像Messenger一样的android应用。在此应用程序中，有一个用于与单人或用户聊天的屏幕。我已将Firebase Firestore用作后端服务器。为了从Firestore中获取数据，我使用了流生成器。当我转到聊天屏幕时，它没有显示任何数据，而是显示了一段时间的进度条，然后消失了。但是，当我执行热重装时，它会显示数据并正常工作，并且我可以看到来自用户的消息，也可以看到我自己的消息。我试图在initState的流构建器中初始化流，但是它不起作用。
Here is the code
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:intl/intl.dart';
import 'package:shared_preferences/shared_preferences.dart';
final containerColor = Color(0xFF112734);
final backgroundColor = Color(0xFF283F4D);
class YourChatChat extends StatelessWidget {
final String inputMessage = '';
final String peerProfieImagUrl;
final String peerId;
final String peerProfileName;
YourChatChat({this.peerProfieImagUrl, this.peerId, this.peerProfileName});
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: backgroundColor,
appBar: AppBar(
backgroundColor: backgroundColor,
elevation: 0,
title: Text(
peerProfileName,
style: TextStyle(
fontSize: 25, fontWeight: FontWeight.bold, letterSpacing: 1.2),
),
actions: <Widget>[
IconButton(
icon: Icon(Icons.more_horiz),
onPressed: () {},
)
],
),
body: YourChatChatScreen(
peerId: peerId,
peerProfileImageUrl: peerProfieImagUrl,
peerProfileName: peerProfileName,
),
);
}
}
class YourChatChatScreen extends StatefulWidget {
final String peerId;
final String peerProfileImageUrl;
final String peerProfileName;
YourChatChatScreen(
{@required this.peerId,
@required this.peerProfileImageUrl,
@required this.peerProfileName});
@override
_YourChatChatScreenState createState() => _YourChatChatScreenState(
peerId: peerId,
peerProfileImageUrl: peerProfileImageUrl,
peerProfileName: peerProfileName);
}
class _YourChatChatScreenState extends State<YourChatChatScreen> {
String peerId;
String currentUserId;
String peerProfileName;
String peerProfileImageUrl;
String groupChatId;
var listMessage;
String inputMessage;
final TextEditingController textEditingController =
new TextEditingController();
final ScrollController listScrollController = new ScrollController();
final FocusNode focusNode = new FocusNode();
SharedPreferences _sharedPreferences;
_YourChatChatScreenState(
{@required this.peerId,
@required this.peerProfileImageUrl,
@required this.peerProfileName});
@override
void initState() {
super.initState();
readDataFromLocalStorage();
}
readDataFromLocalStorage() async {
_sharedPreferences = await SharedPreferences.getInstance();
currentUserId = _sharedPreferences.getString('id') ?? '';
if (currentUserId.hashCode <= peerId.hashCode) {
groupChatId = '$currentUserId - $peerId';
} else {
groupChatId = '$peerId - $currentUserId';
}
}
onMessageSend(String message) {
if (message.trim() != '') {
textEditingController.clear();
var documentReference = Firestore.instance
.collection('messages')
.document(groupChatId)
.collection(groupChatId)
.document(DateTime.now().millisecondsSinceEpoch.toString());
Firestore.instance.runTransaction((transaction) async {
await transaction.set(documentReference, {
'idFrom': currentUserId,
'idTo': peerId,
'message': message,
'timeStamp': DateTime.now().millisecondsSinceEpoch.toString(),
});
});
} else {
Fluttertoast.showToast(msg: 'Nothing to send');
}
}
_buildSendMessage() {
// String message;
return Container(
height: 70,
color: containerColor,
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 10),
child: Container(
decoration: BoxDecoration(
color: backgroundColor,
borderRadius: BorderRadius.circular(20.0),
),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
// IconButton(
// icon: Icon(Icons.photo_library),
// color: Colors.white54,
// iconSize: 25,
// onPressed: () {},
// ),
Expanded(
child: Padding(
padding: const EdgeInsets.only(left: 12),
child: TextField(
// onSubmitted: (value) {
// inputMessage = value;
// },
controller: textEditingController,
decoration: InputDecoration(
border: InputBorder.none,
hintText: 'Send your Message',
hintStyle: TextStyle(
fontWeight: FontWeight.bold,
fontSize: 16,
color: Colors.white24,
letterSpacing: 1.2,
)),
),
),
),
IconButton(
icon: Icon(Icons.send),
color: Colors.white54,
iconSize: 25,
onPressed: () {
print('messsag: ${textEditingController.text.toString()}');
onMessageSend(textEditingController.text.toString());
},
),
],
),
),
),
);
}
@override
Widget build(BuildContext context) {
return SafeArea(
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
StreamBuilder<QuerySnapshot>(
stream: Firestore.instance
.collection('messages')
.document(groupChatId)
.collection(groupChatId)
.snapshots(),
// initialData: null,
builder: (context, snapshot) {
if (!snapshot.hasData) {
if (snapshot.connectionState == ConnectionState.none) {
return Text('none');
}
if (snapshot.connectionState == ConnectionState.waiting) {
return Text('waiting');
}
if (snapshot.connectionState == ConnectionState.active) {
return Text('none');
}
if (snapshot.connectionState == ConnectionState.done) {
return Text('done');
}
return Center(
child: CircularProgressIndicator(
backgroundColor: Colors.white70,
),
);
} else {
if (snapshot.connectionState == ConnectionState.done) {
return Text('done');
}
// if (snapshot.connectionState == ConnectionState.active) {
// return Text('active');
// }
return Expanded(
child: ListView.builder(
reverse: true,
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index) {
var lists = snapshot.data.documents.reversed.toList();
return ChatItem(
peerProfileImageUrl: peerProfileImageUrl,
peerProfileName: peerProfileName,
currentUserProfileName:
_sharedPreferences.getString('profileName') ?? '',
currentUserImageUrl:
_sharedPreferences.getString('profileImage') ??
'',
message: lists[index]['message'],
sendingTime: lists[index]['timeStamp'],
idFrom: lists[index]['idFrom'],
idTo: lists[index]['idTo'],
currentUserId: currentUserId,
);
}),
);
}
},
),
_buildSendMessage()
],
),
);
}
}
class ChatItem extends StatelessWidget {
final String peerProfileImageUrl;
final String currentUserImageUrl;
final String peerProfileName;
final String currentUserProfileName;
final String message;
final String sendingTime;
final String idFrom;
final String idTo;
final String currentUserId;
ChatItem({
this.peerProfileName,
this.peerProfileImageUrl,
this.currentUserImageUrl,
this.currentUserProfileName,
this.message,
this.sendingTime,
this.idFrom,
this.idTo,
this.currentUserId,
});
@override
Widget build(BuildContext context) {
final isMe = currentUserId == idFrom;
return Column(
crossAxisAlignment:
isMe ? CrossAxisAlignment.end : CrossAxisAlignment.start,
children: <Widget>[
Row(
mainAxisAlignment:
isMe ? MainAxisAlignment.end : MainAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 8),
child: CircleAvatar(
backgroundImage: NetworkImage(
isMe ? currentUserImageUrl : peerProfileImageUrl),
),
),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(8),
child: Text(
isMe ? currentUserProfileName : peerProfileName,
style: TextStyle(fontSize: 16, color: Colors.white54),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Material(
elevation: 6,
color:
isMe ? containerColor.withOpacity(0.8) : Colors.white54,
borderRadius: isMe
? BorderRadius.only(
// topRight: Radius.circular(30),
topLeft: Radius.circular(30),
bottomLeft: Radius.circular(30),
bottomRight: Radius.circular(30))
: BorderRadius.only(
topRight: Radius.circular(30),
bottomRight: Radius.circular(30),
bottomLeft: Radius.circular(30)),
child: Padding(
padding: const EdgeInsets.symmetric(
horizontal: 20, vertical: 15),
child: Text(
message,
style: TextStyle(color: Colors.white, fontSize: 16),
),
),
),
),
Padding(
padding: const EdgeInsets.all(6.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget>[
Text(
DateFormat('dd MMM kk:mm').format(
DateTime.fromMillisecondsSinceEpoch(
int.parse(sendingTime))),
style: TextStyle(
color: Colors.white54,
fontSize: 12.0,
fontStyle: FontStyle.italic),
),
],
),
),
// Text(isMe.toString())
],
)
],
),
],
);
}
}