Flutter: save data to a list on another page

Question

I'm absolutely new to flutter and still learning. But couldn't wait to finish my first app until learn all. And also I'm new to programming too.

I'm creating a calculator
Multiply two random numbers and display the value on a text field (an inactive text field)

Actually I need to save that result from that text field with random names to a list on another page.

I've already created that page and can navigate to it using another button.

When I press the "Save" button I need to open a popup.
On that popup I need to add different names
Then I need to save it into that list of another page with current value of the text field.

I have went through a lot of resources and tutorials. But unable to find the answer and still I'm searching.

Optional: I only found how to display the answer on a text field yet. So, that's why I'm using a text field here. And I'm really happy to know about another widgets to display the answer if you can.

The text field code

            Padding(
              padding: const EdgeInsets.fromLTRB(50.0, 50.0, 50.0, 0),
              child:
              TextField(
                controller: volume,
                decoration: InputDecoration(
                  prefixIcon: Icon((Icons.question_answer),),
                  hintText: answer,
                  hintStyle: TextStyle(fontSize: 26.0),
                  labelText: "Volume",
                  labelStyle: TextStyle(fontSize: 18.0),
                  floatingLabelBehavior: FloatingLabelBehavior.always,
                  border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(20.0),),
                ),
                cursorColor: Colors.grey,
                textAlign: TextAlign.center,
                keyboardType: TextInputType.number,
                maxLength: 12,
                maxLines: 1,
                textInputAction: TextInputAction.next,
                style: TextStyle(fontSize: 20.0),
                enabled: false,
              ),
            ),

The calculate button code

            Padding(
              padding: const EdgeInsets.fromLTRB(50.0, 20.0, 50.0, 20.0),
              child: ButtonTheme(
                minWidth: 300.0,
                height: 60.0,
                child: RaisedButton(
                  shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20.0)),
                  child: const Text('Calculate',style: TextStyle(fontSize: 20.0),),
                  color: Colors.blue,
                  textColor: Colors.white,
                  onPressed: (){
                    setState(() {
                      double multiply = constant * double.parse(length.text) * double.parse(perimeter.text) * double.parse(perimeter.text);
                      answer = multiply.toStringAsFixed(2);
                    });
                  },
                ),
              ),
            ),

And the "Save" button code

            Padding(
              padding: const EdgeInsets.fromLTRB(50.0, 10.0, 50.0, 0.0),
              child: ButtonTheme(
                minWidth: 220.0,
                height: 50.0,
                child: RaisedButton(
                  shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20.0)),
                  child: const Text('Save',style: TextStyle(fontSize: 20.0),),
                  color: Colors.blueGrey,
                  textColor: Colors.white,
                  onPressed: (){},
                ),
              ),
            ),

Thank you so much!

You can use Shared Preferances package to save the list. [This Stackoverlow answer may useful.](https://stackoverflow.com/questions/61316208/how-to-save-listobject-to-sharedpreferences-flutter) — Rajen Trivedi, Nov 21 '20 at 05:38

Yadu · Answer 1 · 2020-11-21T06:00:27.940

maintain that list in a separate class,


class ClassWithList{
  List list = [];
  ClassWithList();
}

class Page1 extends StatelessWidget {
  final ClassWithList classWithList;

  const Page1({Key key, this.classWithList}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

class Page2 extends StatelessWidget {
  final ClassWithList classWithList;

  const Page2({Key key, this.classWithList}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

then you can access the same object in both pages

  final ClassWithList classWithList = ClassWithList();
  var w = Page1(classWithList: classWithList,);
  var w2 = Page2(classWithList: classWithList,);

further if you use Provider you can skip passing the class instance

Flutter: save data to a list on another page

1 Answers1