For some reason there is this error(Title) it shows when I try to use ChatsScreen. For Example in the following code the brackets of ChatsScreen are red underlined.

int _selectedItem = 0;
 final List<Widget> _page = [
   Center(child: Text("Home Screen"),),
   ChatsScreen(),
   ProfileScreen(),
 ];

This is the code of the ChatsScreen (There is no error shown in this code):

class ChatsScreen extends StatefulWidget {
  static String routeName = "ChatsScreen";

  UserModel user;
  ChatsScreen(this.user);

  @override
  State<ChatsScreen> createState() => _ChatsScreenState();
}


class _ChatsScreenState extends State<ChatsScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          "Chats"
        ),
        backgroundColor: Colors.orange.shade500,
      ),

      body: StreamBuilder(
        stream: FirebaseFirestore.instance.collection("users").doc(widget.user.uid).collection("messages").snapshots(),
        builder: (context, AsyncSnapshot snapshot) {
          if(snapshot.hasData){
            if(snapshot.data.docs.length < 1) {
              return Center(
                child: Text(
                  "No Chats Available"
                ),
              );
            }
            return ListView.builder(
                itemCount: snapshot.data.docs.length,
                itemBuilder: (context, index) {
                  var friendId = snapshot.data.docs[index].id;
                  var lastMsg = snapshot.data.docs[index]["last_msg"];
                  return FutureBuilder(
                      future: FirebaseFirestore.instance.collection("users").doc(friendId).get(),
                      builder: (context, AsyncSnapshot asyncSnapshot) {
                        if(asyncSnapshot.hasData) {
                          var friend = asyncSnapshot.data;
                          return ListTile(
                            leading: ClipRRect(
                              borderRadius: BorderRadius.circular(80),
                              child: CachedNetworkImage(
                                imageUrl: friend["image"],
                                placeholder: (context, url)=>CircularProgressIndicator(),
                                errorWidget: (context, url, error)=>Icon(Icons.error),
                                height: 50,
                              ),
                            ),
                                title: Text(friend["name"]),
                                subtitle: Container(
                                  child: Text(
                                    "$lastMsg",
                                    style: TextStyle(
                                        color: Colors.grey,
                                        overflow: TextOverflow.ellipsis,
                                    ),
                                  ),
                                ),
                            onTap: () {
                              Navigator.push(context, MaterialPageRoute(builder: (context)=>ChatScreen(
                                  currentUser: widget.user,
                                  friendId: friend["uid"],
                                  friendName: friend["name"],
                                  friendImage: friend["image"],
                              ),
                              ),
                              );
                            }
                          );
                        }
                        return LinearProgressIndicator();
                      },
                  );
                }
            );
          }
          return Center(
            child: CircularProgressIndicator(),
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.search),
        onPressed: () {
          Navigator.push(context, MaterialPageRoute(builder: (context)=> SearchScreen(widget.user)));
        },
      ),
    );
  }
}

I feel like there's something meant to be in the brackets behind ChatsScreen but idk. I hope somebody understands my problem because I for sure don't.

CodePudding user response：

The constructor of your ChatScreen class, expects a parameter:

ChatsScreen(this.user);

So when creating an instance, you should pass in a parameter of UserModel type.

If that's not intended, you should change the constructor to allow the parameter being optional.

CodePudding user response：

You have to give user as parameter like this ChatScreen(user);.

It should look like this, the error will go away

int _selectedItem = 0;
 final List<Widget> _page = [
   Center(child: Text("Home Screen"),),
   ChatsScreen(user),
   ProfileScreen(),
 ];