The method 'saveAndValidate' was called on null.

[irwinOT]

showDialog(
barrierDismissible: false,
context: context,
builder: (BuildContext context) {
return AlertDialog(
actions: [
MaterialButton(
child: Text("Guardar"),
onPressed: () {
if (_formKey.currentState.saveAndValidate()) {
Navigator.pop(context);
print(_formKey.currentState.value );
}
},
),
MaterialButton(
child: Text("Cancelar"),
onPressed: () {
Navigator.pop(context);
_auth.signOut();
},
),
],
content:
FormBuilder(
initialValue: {
'accept_terms': true,
},
key: _formKey,
autovalidate: true,
child: SingleChildScrollView(
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
FormBuilderTextField(
attribute: "name",
decoration: InputDecoration(labelText: "Nombre"),
validators: [
FormBuilderValidators.required(),
FormBuilderValidators.minLength(5),
],
),
FormBuilderTextField(
attribute: "cedula",
decoration:
InputDecoration(labelText: "No. Cédula"),
keyboardType: TextInputType.number,
validators: [
FormBuilderValidators.required(
errorText: "Ingrese la cédula (10 números)",
),
FormBuilderValidators.minLength(10,
errorText: "Debe contener 10 dígitos."),
FormBuilderValidators.maxLength(10,
errorText: "Debe contener 10 dígitos."),
],
),
FormBuilderTextField(
attribute: "phone",
decoration: InputDecoration(
labelText: "Celular", hintText: "0996123456"),
keyboardType: TextInputType.number,
validators: [
FormBuilderValidators.required(),
FormBuilderValidators.numeric(
errorText:
"Ingrese un número celular sin letras."),
FormBuilderValidators.minLength(10,
errorText: "Debe contener 10 dígitos."),
FormBuilderValidators.maxLength(10,
errorText: "Debe contener 10 dígitos."),
],
),
FormBuilderDropdown(
attribute: "gender",
decoration: InputDecoration(labelText: "Género"),
// initialValue: 'Male',
hint: Text('Seleccione género'),
validators: [FormBuilderValidators.required()],
items: ['Masculino', 'Femenino', 'Otro']
.map((gender) => DropdownMenuItem(
value: gender, child: Text("$gender")))
.toList(),
),
FormBuilderCheckbox(
attribute: 'accept_terms',
label: Text("Acepto términos y condiciones."),
validators: [
FormBuilderValidators.requiredTrue(
errorText:
"Usted debe aceptar términos y condiciones de uso para continuar.",
),
],
),
],
),
),
),
);
});

[danvick]

Make sure you've declared and initialized your _formKey as shown in the example

[irwinOT]

Make sure you've declared and initialized your _formKey as shown in the example

already declared: final _formKey = GlobalKey();

[danvick]

I've failed to reproduce your error. If you haven't already solved this, kindly share more of your code - preferably formatted for us to be able to assist easily