How to pass a value bool? in a switch in flutter

Issue

I am making a form with switches in Flutter and I would like to save the value of it, but Flutter doesn’t want a value bool? so I don’t know how to get my value.

Here is my code :

Switch(
   value: _editedProduct.myswitchvalue, //line that causes problem
   onChanged: (bool val) =>
      setState(() {
         _editedProduct = _editedProduct.copyWith(myswitchvalue: val);
     },
   ),
),

And here’s the message of my error

The argument type 'bool?' can't be assigned to the parameter type 'bool'.dart(argument_type_not_assignable)
FormProductModel _editedProduct

Thank you for reading me

Solution

myswitchvalue is of type bool? which means it can either be null or boolean. If you are sure it is not null you can add ! like that:

Switch(
   value: _editedProduct.myswitchvalue!, // watch the !
   onChanged: (bool val) =>
      setState(() {
         _editedProduct = _editedProduct.copyWith(myswitchvalue: val);
     },
   ),
),

read more about null safety in dart here: https://dart.dev/null-safety

Answered By – Yair Chen

Answer Checked By – Marie Seifert (FlutterFixes Admin)

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