Flutter表单验证无效_formKey.currentState.save

问题描述

我有一个登录表单验证程序，该验证程序无法按预期工作。当我将email或password字段留空或输入基于我在validator上设置的内容而无法接受的内容时，虽然显示了错误，但我却被定向到登录单击“登录”按钮成功页面，情况并非如此。我想保留在登录页面上，直到输入正确的值。

登录表单

class SignForm extends StatefulWidget {
  @override
  _SignFormState createState() => _SignFormState();
}

class _SignFormState extends State<SignForm> {
  // GlobalKey This uniquely identifies the Form,and allows validation of the form in a later step.
  final _formKey = GlobalKey<FormState>();
  String email,password;
  bool remember = false;
  final List<String> errors = [];

// func with named parameter
  void addError({String error}) {
    if (!errors.contains(error))
      setState(() {
        errors.add(error);
      });
  }

  void removeError({String error}) {
    if (errors.contains(error))
      setState(() {
        errors.remove(error);
      });
  }

  @override
  Widget build(BuildContext context) {
    return Form(
      key: _formKey,child: Column(
        children: [
          // TextFormField - Creates a [FormField] that contains a [TextField].
          buildEmailFormField(),SizedBox(height: getProportionateScreenHeight(30)),buildPasswordFormField(),Row(
            children: [
              CheckBox(
                value: remember,activeColor: kPrimaryColor,onChanged: (value) {
                  setState(() {
                    remember = value;
                  });
                },),Text("Remember me"),Spacer(),GestureDetector(
                onTap: () => Navigator.pushNamed(
                    context,ForgotPasswordScreen.routeName),child: Text(
                  "Forgot Password?",style: TextStyle(decoration: Textdecoration.underline),)
            ],FormError(errors: errors),SizedBox(height: getProportionateScreenHeight(20)),DefaultButton(                                      < -- WHERE I THINK THE ERROR IS
            text: 'Login',press: () {
              if (_formKey.currentState.validate()) {
                _formKey.currentState.save();                  < -- WHERE I THINK THE ERROR IS
                // if all are valid then go to success screen
                Navigator.pushReplacementNamed(
                    context,LoginSuccessScreen.routeName);
              }
            },)
        ],);
  }

  TextFormField buildPasswordFormField() {
    return TextFormField(
      // obscure visibility of the password
      obscureText: true,onSaved: (newValue) => password = newValue,onChanged: (value) {
        if (value.isNotEmpty && errors.contains(kPassNullError)) {
          removeError(error: kPassNullError);
        } else if (value.length >= 8) {
          removeError(error: kShortPassError);
        }
        // In case a user removed some characters below the threshold,show alert
        else if (value.length < 8 && value.isNotEmpty) {
          addError(error: kShortPassError);
        }
        return null;
      },validator: (value) {
        if (value.isEmpty) {
          addError(error: kPassNullError);
          removeError(error: kShortPassError);
        } else if (value.length < 8 && value.isNotEmpty) {
          addError(error: kShortPassError);
        }
        return null;
      },decoration: Inputdecoration(
        // uses the InputdecorationTheme defined in my theme.dart file
        labelText: "Password",hintText: "Enter your password",// When [FloatingLabelBehavior.always] the label will always float at the top of the field above the content.
        floatingLabelBehavior: FloatingLabelBehavior.always,suffixIcon: CustomSuffixIcon(
          svgIcon: "assets/icons/Lock.svg",);
  }

  TextFormField buildEmailFormField() {
    return TextFormField(
      // Requests a keyboard with ready access to the "@" and "." keys.
      keyboardType: TextInputType.emailAddress,onSaved: (newValue) => email = newValue,onChanged: (value) {
        if (value.isNotEmpty && errors.contains(kEmailNullError)) {
          removeError(error: kEmailNullError);
        } else if (emailValidatorRegExp.hasMatch(value)) {
          removeError(error: kInvalidEmailError);
        } else if (value.isNotEmpty && !emailValidatorRegExp.hasMatch(value)) {
          addError(error: kInvalidEmailError);
          return null;
        }
      },validator: (value) {
        if (value.isEmpty) {
          addError(error: kEmailNullError);
          removeError(error: kInvalidEmailError);
        } else if (value.isNotEmpty && !emailValidatorRegExp.hasMatch(value)) {
          addError(error: kInvalidEmailError);
        }
        return null;
      },decoration: Inputdecoration(
        // uses the InputdecorationTheme defined in my theme.dart file
        labelText: "Email",hintText: "Enter your email",suffixIcon: CustomSuffixIcon(
          svgIcon: "assets/icons/Mail.svg",);
  }
}

解决方法

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