我尝试在 ChatRoomListTile 上创建一个 onTap 函数，它将我导航到 id = chatRoomId 的聊天屏幕。很遗憾，我不知道如何提供 ID。
不幸的是，我对 Flutter 非常缺乏经验，我通过教程制作了这个应用程序......它运行良好，但我仍在学习，非常感谢！
我的 Database.dart
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:signal/helperfunctions/sharedpref_helper.dart';
class DatabaseMethods{
Future addUserInfoToDB(String userId, Map<String, dynamic>userInfoMap)
async {
return FirebaseFirestore.instance
.collection("users")
.doc(userId)
.set(userInfoMap);
}
Future<Stream<QuerySnapshot>> getUserByUserName(String username) async{
return FirebaseFirestore.instance
.collection("users")
.where("username", isEqualTo: username)
.snapshots();
}
Future addMessage(String chatRoomId, String messageId, Map messageInfoMap) async {
return FirebaseFirestore.instance
.collection ("chatrooms")
.doc(chatRoomId)
.collection("chats")
.doc(messageId)
.set(messageInfoMap);
}
updateLastMessageSend(String chatRoomId, Map lastMessageInfoMap){
return FirebaseFirestore.instance
.collection("chatrooms")
.doc(chatRoomId)
.update(lastMessageInfoMap);
}
createChatRoom(String chatRoomId, Map chatRoomInfoMap) async{
final snapShot = await FirebaseFirestore.instance
.collection("chatrooms")
.doc(chatRoomId)
.get();
if(snapShot.exists){
//chatroom already exists
return true;
}else{
//chatroom does not exists
return FirebaseFirestore.instance
.collection("chatrooms")
.doc(chatRoomId)
.set(chatRoomInfoMap);
}
}
Future<Stream<QuerySnapshot>> getChatRoomMessages(chatRoomId) async {
return FirebaseFirestore.instance
.collection("chatrooms")
.doc(chatRoomId)
.collection("chats")
.orderBy("ts", descending: true)
.snapshots();
}
// Future<Stream<QuerySnapshot>> openChatRoom(String chatRoomId) async{
// return FirebaseFirestore.instance
// .collection("chatrooms")
// .doc(chatRoomId)
// .collection("chats")
// .snapshots();
// }
Future<Stream<QuerySnapshot>> getChatRooms() async {
String myUsername = await SharedPreferenceHelper().getUserName();
return FirebaseFirestore.instance
.collection("chatrooms")
.orderBy("lastMessageSendTs", descending: true)
.where("users",arrayContains: myUsername)
.snapshots();
}
Future<QuerySnapshot> getUserInfo(String username) async {
return await FirebaseFirestore.instance
.collection("users")
.where("username", isEqualTo: username)
.get();
}
}
和我的 home.dart
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:signal/helperfunctions/sharedpref_helper.dart';
import 'package:signal/services/auth.dart';
import 'package:signal/services/database.dart';
import 'package:signal/views/signin.dart';
import 'services/colorpicker.dart';
import 'chatscreen.dart';
class Home extends StatefulWidget {
@override
_HomeState createState() => _HomeState();
}
class _HomeState extends State<Home> {
bool isSearching = false;
String myName, myProfilePic, myUserName, myEmail, messageSentTs;
Stream usersStream, chatRoomsStream;
TextEditingController searchUsernameEditingController =
TextEditingController();
getMyInfoFromSharedPreference() async{
myName = await SharedPreferenceHelper().getDisplayName();
myProfilePic = await SharedPreferenceHelper().getUserProfileUrl();
myUserName = await SharedPreferenceHelper().getUserName();
myEmail = await SharedPreferenceHelper().getUserEmail();
}
//dieser string sollte eigentlich aus sicherheitsgründen random generiert werden
getChatRoomIdByUsernames(String a, String b){
if(a.substring(0,1).codeUnitAt(0) > b.substring(0,1).codeUnitAt(0)){
return "$b\_$a";
}else{
return "$a\_$b";
}
}
onSearchBtnClick() async {
isSearching = true;
setState(() {});
usersStream = await DatabaseMethods()
.getUserByUserName(searchUsernameEditingController.text);
setState(() {});
}
Widget chatRoomsList(){
return StreamBuilder(
stream: chatRoomsStream,
builder: (context, snapshot){
return snapshot.hasData
? ListView.builder(
itemCount: snapshot.data.docs.length,
shrinkWrap: true,
itemBuilder: (context, index){
DocumentSnapshot ds = snapshot.data.docs[index];
return ChatRoomListTile(ds["lastMessage"], ds.id,myUserName);
})
: Center(child: CircularProgressIndicator());
},
);
}
// print("this is the values we have $myUserName $username"));
// Chatroom ID Kontrolle ( achtung beim randomisen der CRId)
Widget searchUserListTile({String profileUrl, name, username, email}){
return GestureDetector(
onTap: (){
var chatRoomId = getChatRoomIdByUsernames(myUserName, username);
Map<String, dynamic> chatRoomInfoMap = {
"users" : [myUserName, username]
};
DatabaseMethods().createChatRoom(chatRoomId, chatRoomInfoMap);
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => ChatScreen(username, name)
)
);
},
child: Row(
children: [
ClipRRect(
borderRadius: BorderRadius.circular(30),
child: Image.network(
profileUrl,
height: 20,
width: 20,
),
),
SizedBox(width: 12),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children:[
Text(name),
Text(email),
],
)
],
),
);
}
Widget searchUsersList(){
return StreamBuilder(
stream: usersStream,
builder: (context, snapshot){
return snapshot.hasData
? ListView.builder(
itemCount: snapshot.data.docs.length,
shrinkWrap: true,
itemBuilder: (context, index){
DocumentSnapshot ds = snapshot.data.docs[index];
return searchUserListTile(
profileUrl: ds["imgUrl"],
name: ds["name"],
username: ds["username"],
email: ds["email"]
);
},
) : Center(child: CircularProgressIndicator(),);
}
);
}
getChatRooms() async {
chatRoomsStream = await DatabaseMethods().getChatRooms();
setState(() {});
}
onScreenLoaded() async {
await getMyInfoFromSharedPreference();
getChatRooms();
}
@override
void initState() {
onScreenLoaded();
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Color.fromRGBO(233, 240, 244, 1),
appBar: AppBar(
title: Image.asset('assets/images/logo.png', width: 40,),
elevation: 0.0,
backgroundColor: Colors.white,
actions: [
InkWell(
onTap: (){
AuthMethods().signOut().then((s) {
Navigator.pushReplacement(context, MaterialPageRoute
(builder: (context) => SignIn()));
});
},
child: Container(
padding: EdgeInsets.symmetric(horizontal: 16),
child: Icon(Icons.exit_to_app)),
)
],
),
body: Container(
margin: EdgeInsets.symmetric(horizontal: 20),
child: Column(
children: [
Row(
children: [
isSearching
? GestureDetector(
onTap: (){
isSearching = false;
searchUsernameEditingController.text = "";
setState(() {});
},
child: Padding(
padding: EdgeInsets.only(right: 12),
child: Icon(Icons.arrow_back)),
) : Container(),
Expanded(
child: Container(
// Disable Searchbar
width: 0,
height: 0,
margin: EdgeInsets.symmetric(vertical: 16),
padding: EdgeInsets.symmetric(horizontal:16),
decoration: BoxDecoration
(border: Border.all(
color: Colors.black87,
width: 1,
style: BorderStyle.solid), borderRadius: BorderRadius.circular(24)),
child: Row(
children: [
Expanded(
child: TextField(
controller: searchUsernameEditingController,
decoration: InputDecoration(
border: InputBorder.none, hintText: "Finde einen Freund"),
)),
GestureDetector(
onTap:(){
if(searchUsernameEditingController.text != ""){
onSearchBtnClick();
}
},
// Disable Search Icon
// child: Icon(Icons.search),
)
],
),
),
)
]
),
isSearching ? searchUsersList() : chatRoomsList()
],
),
),
);
}
}
class ChatRoomListTile extends StatefulWidget {
final String lastMessage, chatRoomId, myUsername;
ChatRoomListTile(this.lastMessage, this.chatRoomId, this.myUsername);
@override
_ChatRoomListTileState createState() => _ChatRoomListTileState();
}
class _ChatRoomListTileState extends State<ChatRoomListTile> {
String profilePicUrl ="", name="", username="";
getThisUserInfo() async {
username = widget.chatRoomId.replaceAll(widget.myUsername, "").replaceAll("_", "");
QuerySnapshot querySnapshot = await DatabaseMethods().getUserInfo(username);
name = "${querySnapshot.docs[0]["name"]}";
profilePicUrl = "${querySnapshot.docs[0]["imgUrl"]}";
setState(() {});
}
@override
void initState() {
getThisUserInfo();
super.initState();
}
@override
Widget build(BuildContext context) {
return Container(
margin: EdgeInsets.symmetric(vertical: 2, horizontal: 0,),
padding: EdgeInsets.symmetric(horizontal:12,vertical: 20,),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(8),
),
child: Row(
children: [
ClipRRect(
borderRadius: BorderRadius.circular(8),
child: Image.network(
profilePicUrl,
height: 35,
width: 35,
),
),
SizedBox(width: 15),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
name,
style: TextStyle(
fontSize: 14,
fontFamily: 'Roboto',
color: Color.fromRGBO(57, 59, 85, 0.8),
fontWeight: FontWeight.w500,
),
),
SizedBox(height: 5),
Container(
width: (MediaQuery.of(context).size.width) - 150,
child: Text(
widget.lastMessage,
style: new TextStyle(
fontSize: 13.0,
fontFamily: 'Roboto',
color: Color.fromRGBO(171, 183, 201, 1),
fontWeight: FontWeight.w400,
),
overflow: TextOverflow.ellipsis,
maxLines: 1,
),
),
],
)
],
),
);
}
}
答案 0 :(得分：1)
您可以将 id 作为构造函数从 listTile 传递，
Navigator.of(context).push.... ChatScreen(id: chatRoomId)
如此，在 ChatScreen 中，您可以像这样接收它
class ChatScreenextends StatefulWidget {
final String id;
ChatScreen({requried this.id});
@override
_ChatScreenState createState() => _ChatScreenState ();
}
class _ChatScreenState extends State<ChatScreen> {
如果它是一个无状态的 Widget 类，你可以直接访问 id 作为 id，如果它是一个有状态的 Widget 则 widget.id ，
另一种方法是作为 Navigator 参数传递，您可以查看文档以获取更多信息 Flutter Docs
答案 1 :(得分：0)
您好，非常感谢您抽出宝贵时间……我尝试实施它，但不幸的是我遇到了错误。在这里，我添加到 home.dart 的 GestureDetector ::: 我也尝试将 id: chatRoomId 更改为 this.Id 或只是 chatRoomId .. 但它始终带有下划线并出错：
Widget build(BuildContext context) {
return GestureDetector(
onTap: () {
Navigator.push(context,
MaterialPageRoute(builder: (context) => ChatScreen(id: chatRoomId)));
},
child: Container(
margin: EdgeInsets.symmetric(vertical: 2, horizontal: 0,),
padding: EdgeInsets.symmetric(horizontal:12,vertical: 20,),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.circular(8),
),
这里是 chatscreen.dart 的更新
class ChatScreen extends StatefulWidget {
final String chatWidthUsername, name, id;
ChatScreen(this.chatWidthUsername, this.name, {this.id});
@override
_ChatScreenState createState() => _ChatScreenState();
}
class _ChatScreenState extends State<ChatScreen> {
String chatRoomId, messageId = "";
Stream messageStream;
String myName, myProfilePic, myUserName, myEmail;
TextEditingController messageTextEditingController = TextEditingController();
再次感谢！ 问候 亚历克斯