create a validator in flutter
ElevatedButton(
onPressed: () {
// Validate returns true if the form is valid, otherwise false.
if (_formKey.currentState.validate()) {
// If the form is valid, display a snackbar. In the real world,
// you'd often call a server or save the information in a database.
Scaffold
.of(context)
.showSnackBar(SnackBar(content: Text('Processing Data')));
}
},
child: Text('Submit'),
);