Flutter validation called on null in Login page - flutter

Question

I'm trying to do my first app but I don't know how to use validator.
I tried to move all in myLogin class and i tried to split my code to find the problem.
I set formkey as global varible (with mail and pass variables).
import 'package:flutter/material.dart';
String _email, _password;
final formKey = new GlobalKey < FormState > ();
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
...
}
class myLogin extends StatefulWidget {
#override
_myLogin createState() => _myLogin();
}
class _myLogin extends State < myLogin > {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: "Title",
home: Scaffold(
body: (
Column(
children: [
titleRow,
],
)
)
),
);
}
}
This is my screen.
Widget titleRow = Container(
padding: const EdgeInsets.fromLTRB(40, 40, 40, 40),
child: Form(
key: formKey,
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Expanded(
child: Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: [
TextFormField(
decoration: InputDecoration(labelText: "Email: "),
validator: (value) => !value.contains('#') ? "Not a valid Email" : null,
onSaved: (value) => _email = value
),
TextFormField(
decoration: InputDecoration(labelText: "Password: "),
validator: (value) => value.length < 8 ? "At least 8 character" : null,
onSaved: (value) => _password = value,
obscureText: true
),
OutlineButton(
child: new Text("Sign In"),
onPressed: funLogin(),
shape: new RoundedRectangleBorder(borderRadius: new BorderRadius.circular(30.0))
)
]
)
)
]
)
)
);
funLogin() {
final form = formKey.currentState;
if (form.validate()) {
form.save();
print(_email);
print(_password);
}
}
The Android emulator return error:
"NoSuchMethodError: The method validate was called on null"

Answer 1

You are using the function inside an onpressed so you should use it like this
onPressed : ()=> your function