相关疑难解决方法(0)

一切都很好，但是当我升级我的云 Firestore 依赖项时。我开始收到错误消息“未为类型 'Object' 定义运算符 '[]'。”。这个错误出现在所有 4 个 userData.data()[""] 之前，

class BaseProvider with ChangeNotifier {
  //instances of firebase

  final FirebaseAuth _auth = FirebaseAuth.instance;

  final CollectionReference postsCollection =
      FirebaseFirestore.instance.collection("posts");

  final CollectionReference userCollection =
      FirebaseFirestore.instance.collection("users");

  //Creating post

  Future addPost(
    
  ) async {
    DocumentSnapshot userData =
        await userCollection.doc(_auth.currentUser.uid).get();
    return await postsCollection.doc().set({
      "id": _auth.currentUser.uid,
      "sellername": userData.data()["name"],      //Error
      "sellercontact": userData.data()["phone"],  //Error
      "sellercity": userData.data()["city"],      //Error
      "sellerstate": userData.data()["state"],    //Error
      
    });
  }

我的代码在以下错误中给出了我在此行中从 firebase 访问用户名时遇到的问题

snapshot.data['username']

它给出了上面提到的错误

我知道访问地图数据的唯一方法是这样

FutureBuilder<Object>(
  future: FirebaseFirestore.instance
   .collection('users')
   .doc(userId)
   .get(),
  builder: (context, snapshot) {
    if (snapshot.connectionState == ConnectionState.waiting) {
      return Text("Loading...");
    }
    return Text(
      snapshot.data['username'],
      style: TextStyle(
        fontWeight: FontWeight.bold,
      ),
    );
  }
),