c# - 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，我觉得我的方法有点多余。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，我已从代码中删除实际验证。

代码:

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;
        }
    }

}

调用代码:

    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

为姓氏和名字定义一个枚举。

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 扩展方法来读取描述:

 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();
    }
}

然后在“提交”按钮上，将描述分配给标签文本。

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

此处 ValidateFirstName 和 ValidateLastName 返回 NameValidation 枚举类型。