if (_formKey.currentState!.validate()) {
                      try {
                        final newUser =
                            await _auth.createUserWithEmailAndPassword(
                                email: email.text, password: password.text);
                        if (newUser != null) {
                          // Navigator.push(
                          //     context,
                          //     MaterialPageRoute(
                          //       builder: (context) => DashboardScreen(),
                          //     ));
                          Navigator.pushNamed(context, 'dashboard');
                        }

                        setState(() {});
                      } catch (e) {
                        print(e);
                      }
                    }
                  },

此警告显示在Navigator.pushNamed（context，“ Jmeter 板”）上;试图导航到 Jmeter 板屏幕。