Firebase Flutter Does Not Recognize My String as Parameter-CodePudding

I am trying to get user email,save to shared preferences and use as collection name in another file.

my code to save

Future<void> saveEmail() async {
var sharedPreferences = await SharedPreferences.getInstance();
sharedPreferences.setString("email", _emailKontroller.text);}

no problem here, I can save data to sharedPreferences and read data from another file.

my code to read

  @override
void initState() {
// TODO: implement initState
void initilaizeEmail() async {
  var sharedPreferences = await SharedPreferences.getInstance();
  _email = sharedPreferences.getString("email");
  print(_email);
}

initilaizeEmail();
setState(() {});

}

output

I/flutter ( 3274): [email protected]

where I use as parameter my sharedPreferences Data:

 query: FirebaseFirestore.instance
        .collection("test")
        .doc("$_email")
        .collection("class 0"),
    // to fetch real-time data
    isLive: false,

I can not see anything on screen but, if I delete

_email

and type "[email protected]" manually everything works.What is the problem?

CodePudding user response：

The problem is that initilaizeEmail is an async method, and you're not waiting for its result. To fix this:

await initilaizeEmail();

I also recommend fixing the name of the method to be initializeEmail. While it won't change the behavior, spelling mistakes tend distract from other problems.

CodePudding user response：

I solved my problem with using

Future Builder