ElevatedButton(
  onPressed: () {
    // Validate will return true if the form is valid, or false if
    // the form is invalid.
    if(_formKey.currentState.validate()) {
        // Process data.
    }
  },
  child: Padding(
      padding: const EdgeInsets.symmetric(vertical: 15.0, horizontal: 10),
    child: Text('Entrar'),
  )
)