Flutter : How to calculate value from textfields in listview.builder - dart

Question

I want to retrieve and calculate input values from the textfield in listview .. how to achieve that?

Answer 1

You should define a list of TextEditingController with the same length of your listview, then assign each TextField in your list an object of this array, which will enable you to retrieve the value whether when editing or when completed. This is an example of what I've said :
List<TextEditingController> textFieldControllers ;
in your list :
textFieldControllers[index] = new TextEditingController() ;
new TextField(controller: textFieldControllers[index]);
after that you can retrieve the value by :
textFieldControllers[index].text

Answer 2

Brilliant. Added some stuff below to suit my use case.
First define a List like so List<TextEditingController> textFieldControllers=[];
then iterate through the the list used in creating the widgets in the List.builder like so.
for (var i = 0; i < typesItem.length; i++) {
textFieldControllers.add(TextEditingController());
}
where typesItem is the List item used in creating the Listbuilder widgets so as to maintain same lenght with your widgets dynamically.You can run this code on your initState method
there after goto your List.builder widget and initialise your controller like so.
textFieldControllers[index] = TextEditingController() ;
and set your TextField controllers in your return method like so
textFieldControllers[index]
You can therefore get all your value by using
textFieldControllers[index].text;
You can manipulate to suit use your case as you want

Answer 3

List<TextEditingController> machPresent=[];
machPresent.add(TextEditingController(text: ''));
Container(
height: mainScreenHeight * 0.06,
width: mainScreenWidth * 0.3,
child: TextFormField(
keyboardType: TextInputType.number,
controller: machPresent[index],
enabled: true,
textAlign: TextAlign.center,
),
),
),
Press an action from a button
Container(
height: mainScreenHeight * 0.06,
width: mainScreenWidth * 0.3,
child: RaisedButton(
onPressed: () {
submitForm(index);},
child: Text('Submit',textAlign: TextAlign.center),
),
),
dynamic submitForm(int index) {
var machValue=machPresent[index].text;
var f= machValue;
print(f);
}
Result
I/flutter ( 7914): fff888- -- -- -Select Status
I/flutter ( 7914): sourav- -- -- -Select Status