如何使用Enum为数据验证提供描述性状态

Question

我需要使用enum，以便我的应用程序中的验证易于阅读，并且易于理解和管理：

但是，我觉得我的做法有点无关紧要。有没有办法用更少的代码来做到这一点？

请注意：为简洁起见，我已从代码中删除了实际验证。

码：

public enum LastName
{
    ContainNumbers,
    ContainIlligalCharacters,
    ContainEmptyString,
    PassedValidation,
}

public enum FirstName
{
    ContainNumbers,
    ContainIlligalCharacters,
    ContainEmptyString,
    PassedValidation,
}
public class DataMember 
{

    int _lastNameState;
    int _firstNameState;

    public DataMember(string lastName, string firstName)
    {
        LastName lName;
        FirstName fName;

        _lastNameState = (int)(lName = (lastName == "A" ? 
            LastName.PassedValidation : LastName.ContainEmptyString));

        _firstNameState = (int)(fName = (firstName == "B" ? 
            FirstName.PassedValidation : FirstName.ContainEmptyString));
    }

    public int UserLastName
    {
        get
        {
            return _lastNameState;
        }
        set
        {
            _lastNameState = value;
        }
    }

    public int UserFirstName
    {
        get
        {
            return _firstNameState;
        }
        set
        {
            _firstNameState = value;
        }
    }

}

来电代码：

    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        DataMember dataMember = new DataMember(txtLastName.Text, txtFirstName.Text);

   bool isValidLastName = (dataMember.UserLastName ==  (int)LastName.PassedValidation);
   bool isValidFirstName = (dataMember.UserFirstName == (int)FirstName.PassedValidation);

     lblDisplayLastNameStatus.Text = isValidLastName.ToString();
     lblDisplayFirstNameStatus.Text = isValidFirstName.ToString();
    }

Answer 1

以下是顶级代码的更新，以便进行更清晰的基本验证。 [Flags]属性的好处是它可以扩展你知道所有无效状态的能力。换句话说，您可以与客户共享一条消息，表明其名称包含数字和非法字符。

也没有必要将枚举转换为int。您可以使用与int相同的方式比较枚举。您还可以使用默认属性。

[Flags]
public enum NameValidation
{
    PassedValidation = 0,
    ContainNumbers = 1,
    ContainIllegalCharacters = 2,
    ContainEmptyString = 4,
}

public class DataMember 
{
    public NameValidation FirstNameState {get; set;}
    public NameValidation LastNameState {get; set;}

    public DataMember(string lastName, string firstName)
    {
        FirstNameState = ValidateName(firstName);
        LastNameState = ValidateName(lastName);
    }

    private NameValidation ValidateName(string name)
    {
        var validation = NameValidation.PassedValidation;
        if(string.IsNullOrEmpty(name)) validation |= NameValidation.ContainEmptyString;
        //Validate illegal characters
        //Validate numbers
        return validation;
    }
}

我将这些打印输出为真/假，因为这是原始调用所做的。但是，您也可以打印出标志值以提供验证状态。

protected void btnSubmit_Click(object sender, EventArgs e)
{
    DataMember dataMember = new DataMember(txtLastName.Text, txtFirstName.Text);

    lblDisplayLastNameStatus.Text = (dataMember.LastNameState ==  NameValidation.PassedValidation).ToString();
    lblDisplayFirstNameStatus.Text = (dataMember.FirstNameState ==  NameValidation.PassedValidation).ToString();
}

Answer 2

为姓氏和名字定义单个枚举。

public enum NameValidation
{
   [Description("Contains Numbers"]
   ContainNumbers,

   [Description("Contains Illigal Characters"]
   ContainIlligalCharacters,

   [Description("Contains empty strings"]
   ContainEmptyString,

   [Description("Success. Passed Valiation"]
   PassedValidation,
}

有一个Enum Helper扩展方法来阅读描述：

 public static class EnumHelper
{
    public static string GetDescription<T>(this T enumVal) where T : struct
    {
        Type type = enumVal.GetType();
        if (!type.IsEnum)
        {
            throw new ArgumentException("Must be enum type","enumVal");
        }
        MemberInfo[] memberInfo = type.GetMember(enumVal.ToString());
        if (memberInfo.Length > 0)
        {
            object[] attrs = memberInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);

            if (attrs.Length > 0)
            {
                return ((DescriptionAttribute)attrs[0]).Description;
            }
        }
        return enumVal.ToString();
    }
}

在“提交”按钮上，将描述分配给标签文本。

lblDisplayFirstNameStatus.Text= ValidateFirstName().GetDescription();
lblDisplayFirstNameStatus.Text= ValidateLastName().GetDescription();

这里ValidateFirstName和ValidateLastName返回NameValidation枚举类型。

Answer 3

为什么需要两个相同的枚举？只需将其命名并巧妙地命名变量即可。

public enum NameValidation
{
    ContainNumbers,
    ContainIlligalCharacters,
    ContainEmptyString,
    PassedValidation,
}

NameValidation lNameValidation;
NameValidation fNameValidation;

如果要定义两个，但它们具有不同但相似的值集，则可以始终定义类并继承。

public abstract class BaseValidation {
    public const ContainNumbers int = 1;
    public const ContainIlligalCharacters = 2;
    public const ContainEmptyString = 3;
    public const PassedValidation = 4
}

public class FirstName: BaseValidation {
    public const SomethingDifferent = 5;
}

public class LastName: BaseValidation {
    public const SomethingMoreDifferent = 5;
    public const SomethingEvenMoreDifferent = 6;
}

我不推荐我的第二个解决方案，因为它太过分了，但这是你可以采取的另一种方式。