How to read value in the createState method of StatefulWidget











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1
down vote

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Hello I want to read the value from the SharedPreferences inside the createState of the StatefulWidget.



I tried to add async after the method but it doesn't work. What is the correct way to do ?



class LoginScreen extends StatefulWidget {
@override
_LoginScreenState createState() {

// check if user is logged. If logged then send user to dashboard else keep it here


return new _LoginScreenState();
}
}









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  • That's not a good idea. Do it in initState() of _LoginScreenState() instead.
    – Günter Zöchbauer
    Nov 22 at 16:53










  • How to do there ?
    – N Sharma
    Nov 22 at 16:56










  • Nothing special, just do it and use setState(() { ...}) to update the value when it's available. This is a FAQ and there should be several answers for that on StackOverflow already.
    – Günter Zöchbauer
    Nov 22 at 16:58






  • 1




    I'd use didChangeDependencies instead in case the user disconnect. User details most likely comes from an InheritedWidget anyway
    – Rémi Rousselet
    Nov 22 at 17:03















up vote
1
down vote

favorite












Hello I want to read the value from the SharedPreferences inside the createState of the StatefulWidget.



I tried to add async after the method but it doesn't work. What is the correct way to do ?



class LoginScreen extends StatefulWidget {
@override
_LoginScreenState createState() {

// check if user is logged. If logged then send user to dashboard else keep it here


return new _LoginScreenState();
}
}









share|improve this question






















  • That's not a good idea. Do it in initState() of _LoginScreenState() instead.
    – Günter Zöchbauer
    Nov 22 at 16:53










  • How to do there ?
    – N Sharma
    Nov 22 at 16:56










  • Nothing special, just do it and use setState(() { ...}) to update the value when it's available. This is a FAQ and there should be several answers for that on StackOverflow already.
    – Günter Zöchbauer
    Nov 22 at 16:58






  • 1




    I'd use didChangeDependencies instead in case the user disconnect. User details most likely comes from an InheritedWidget anyway
    – Rémi Rousselet
    Nov 22 at 17:03













up vote
1
down vote

favorite









up vote
1
down vote

favorite











Hello I want to read the value from the SharedPreferences inside the createState of the StatefulWidget.



I tried to add async after the method but it doesn't work. What is the correct way to do ?



class LoginScreen extends StatefulWidget {
@override
_LoginScreenState createState() {

// check if user is logged. If logged then send user to dashboard else keep it here


return new _LoginScreenState();
}
}









share|improve this question













Hello I want to read the value from the SharedPreferences inside the createState of the StatefulWidget.



I tried to add async after the method but it doesn't work. What is the correct way to do ?



class LoginScreen extends StatefulWidget {
@override
_LoginScreenState createState() {

// check if user is logged. If logged then send user to dashboard else keep it here


return new _LoginScreenState();
}
}






android ios flutter sharedpreferences






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share|improve this question











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share|improve this question










asked Nov 22 at 16:52









N Sharma

6,97243141289




6,97243141289












  • That's not a good idea. Do it in initState() of _LoginScreenState() instead.
    – Günter Zöchbauer
    Nov 22 at 16:53










  • How to do there ?
    – N Sharma
    Nov 22 at 16:56










  • Nothing special, just do it and use setState(() { ...}) to update the value when it's available. This is a FAQ and there should be several answers for that on StackOverflow already.
    – Günter Zöchbauer
    Nov 22 at 16:58






  • 1




    I'd use didChangeDependencies instead in case the user disconnect. User details most likely comes from an InheritedWidget anyway
    – Rémi Rousselet
    Nov 22 at 17:03


















  • That's not a good idea. Do it in initState() of _LoginScreenState() instead.
    – Günter Zöchbauer
    Nov 22 at 16:53










  • How to do there ?
    – N Sharma
    Nov 22 at 16:56










  • Nothing special, just do it and use setState(() { ...}) to update the value when it's available. This is a FAQ and there should be several answers for that on StackOverflow already.
    – Günter Zöchbauer
    Nov 22 at 16:58






  • 1




    I'd use didChangeDependencies instead in case the user disconnect. User details most likely comes from an InheritedWidget anyway
    – Rémi Rousselet
    Nov 22 at 17:03
















That's not a good idea. Do it in initState() of _LoginScreenState() instead.
– Günter Zöchbauer
Nov 22 at 16:53




That's not a good idea. Do it in initState() of _LoginScreenState() instead.
– Günter Zöchbauer
Nov 22 at 16:53












How to do there ?
– N Sharma
Nov 22 at 16:56




How to do there ?
– N Sharma
Nov 22 at 16:56












Nothing special, just do it and use setState(() { ...}) to update the value when it's available. This is a FAQ and there should be several answers for that on StackOverflow already.
– Günter Zöchbauer
Nov 22 at 16:58




Nothing special, just do it and use setState(() { ...}) to update the value when it's available. This is a FAQ and there should be several answers for that on StackOverflow already.
– Günter Zöchbauer
Nov 22 at 16:58




1




1




I'd use didChangeDependencies instead in case the user disconnect. User details most likely comes from an InheritedWidget anyway
– Rémi Rousselet
Nov 22 at 17:03




I'd use didChangeDependencies instead in case the user disconnect. User details most likely comes from an InheritedWidget anyway
– Rémi Rousselet
Nov 22 at 17:03












2 Answers
2






active

oldest

votes

















up vote
3
down vote













You don't.



You should not have anything inside createState beside the state creation. If you want to do these kind of check, do them inside the State class instead:



class MyState extends State<MyWidget> {
@override
void didChangeDependencies() {
// check if the user is logged
}
}





share|improve this answer




























    up vote
    1
    down vote













    Don't use createState to read the values, you can use initState or FutureBuilder maybe.



    class LoginScreen extends StatefulWidget {
    @override
    _LoginScreenState createState() => _LoginScreenState();
    }

    class _LoginScreenState extends State<LoginScreen> {
    String value;

    _readPreference() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    //refresh your screen based on the current parameter
    setState(() {
    value = prefs.getString("your_value_key");
    });
    }

    @override
    void initState() {
    _readPreference();
    super.initState();
    }

    @override
    Widget build(BuildContext context) {
    return Container();
    }
    }





    share|improve this answer





















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      2 Answers
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      2 Answers
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      up vote
      3
      down vote













      You don't.



      You should not have anything inside createState beside the state creation. If you want to do these kind of check, do them inside the State class instead:



      class MyState extends State<MyWidget> {
      @override
      void didChangeDependencies() {
      // check if the user is logged
      }
      }





      share|improve this answer

























        up vote
        3
        down vote













        You don't.



        You should not have anything inside createState beside the state creation. If you want to do these kind of check, do them inside the State class instead:



        class MyState extends State<MyWidget> {
        @override
        void didChangeDependencies() {
        // check if the user is logged
        }
        }





        share|improve this answer























          up vote
          3
          down vote










          up vote
          3
          down vote









          You don't.



          You should not have anything inside createState beside the state creation. If you want to do these kind of check, do them inside the State class instead:



          class MyState extends State<MyWidget> {
          @override
          void didChangeDependencies() {
          // check if the user is logged
          }
          }





          share|improve this answer












          You don't.



          You should not have anything inside createState beside the state creation. If you want to do these kind of check, do them inside the State class instead:



          class MyState extends State<MyWidget> {
          @override
          void didChangeDependencies() {
          // check if the user is logged
          }
          }






          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered Nov 22 at 17:02









          Rémi Rousselet

          22.7k24076




          22.7k24076
























              up vote
              1
              down vote













              Don't use createState to read the values, you can use initState or FutureBuilder maybe.



              class LoginScreen extends StatefulWidget {
              @override
              _LoginScreenState createState() => _LoginScreenState();
              }

              class _LoginScreenState extends State<LoginScreen> {
              String value;

              _readPreference() async {
              SharedPreferences prefs = await SharedPreferences.getInstance();
              //refresh your screen based on the current parameter
              setState(() {
              value = prefs.getString("your_value_key");
              });
              }

              @override
              void initState() {
              _readPreference();
              super.initState();
              }

              @override
              Widget build(BuildContext context) {
              return Container();
              }
              }





              share|improve this answer

























                up vote
                1
                down vote













                Don't use createState to read the values, you can use initState or FutureBuilder maybe.



                class LoginScreen extends StatefulWidget {
                @override
                _LoginScreenState createState() => _LoginScreenState();
                }

                class _LoginScreenState extends State<LoginScreen> {
                String value;

                _readPreference() async {
                SharedPreferences prefs = await SharedPreferences.getInstance();
                //refresh your screen based on the current parameter
                setState(() {
                value = prefs.getString("your_value_key");
                });
                }

                @override
                void initState() {
                _readPreference();
                super.initState();
                }

                @override
                Widget build(BuildContext context) {
                return Container();
                }
                }





                share|improve this answer























                  up vote
                  1
                  down vote










                  up vote
                  1
                  down vote









                  Don't use createState to read the values, you can use initState or FutureBuilder maybe.



                  class LoginScreen extends StatefulWidget {
                  @override
                  _LoginScreenState createState() => _LoginScreenState();
                  }

                  class _LoginScreenState extends State<LoginScreen> {
                  String value;

                  _readPreference() async {
                  SharedPreferences prefs = await SharedPreferences.getInstance();
                  //refresh your screen based on the current parameter
                  setState(() {
                  value = prefs.getString("your_value_key");
                  });
                  }

                  @override
                  void initState() {
                  _readPreference();
                  super.initState();
                  }

                  @override
                  Widget build(BuildContext context) {
                  return Container();
                  }
                  }





                  share|improve this answer












                  Don't use createState to read the values, you can use initState or FutureBuilder maybe.



                  class LoginScreen extends StatefulWidget {
                  @override
                  _LoginScreenState createState() => _LoginScreenState();
                  }

                  class _LoginScreenState extends State<LoginScreen> {
                  String value;

                  _readPreference() async {
                  SharedPreferences prefs = await SharedPreferences.getInstance();
                  //refresh your screen based on the current parameter
                  setState(() {
                  value = prefs.getString("your_value_key");
                  });
                  }

                  @override
                  void initState() {
                  _readPreference();
                  super.initState();
                  }

                  @override
                  Widget build(BuildContext context) {
                  return Container();
                  }
                  }






                  share|improve this answer












                  share|improve this answer



                  share|improve this answer










                  answered Nov 22 at 17:02









                  diegoveloper

                  8,98611225




                  8,98611225






























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