Flutter for Beginners

Using a key

The Form widget is used with the companion of a key of the FormState type, that contains helpers to manage all of the children of its FormField instances:

final _key = GlobalKey<FormFieldState<String>>();...Form(  key: _key,  child: Column(    children: <Widget>[      TextFormField(),      TextFormField(),    ],  ),);

Then, we can use the key to retrieve the Form associated state and call its validation with _key.currentState.validate(). Now, let's have a look at the second option.