Define String ENUM in VB.Net

Question

I am using Window Application for my project. There is situation where i need to define string enum and using it in my project.

i.e.

Dim PersonalInfo         


        

Answer 1

How about using Tagging. Something like:

Public Enum MyEnum
Contact
PersonalInfo
End Enum

You would have to write the StringValue attribute as:

Public Class StringValueAttribute
    Inherits Attribute

    Public Property Value As String
    Public Sub New(ByVal val As String)
        Value = val
    End Sub

End Class

To get it out:

 Public Function GetEnumByStringValueAttribute(value As String, enumType As Type) As Object
    For Each val As [Enum] In [Enum].GetValues(enumType)
        Dim fi As FieldInfo = enumType.GetField(val.ToString())
        Dim attributes As StringValueAttribute() = DirectCast(fi.GetCustomAttributes(GetType(StringValueAttribute), False), StringValueAttribute())
        Dim attr As StringValueAttribute = attributes(0)
        If attr.Value = value Then
            Return val
        End If
    Next
    Throw New ArgumentException("The value '" & value & "' is not supported.")
End Function

Public Function GetEnumByStringValueAttribute(Of YourEnumType)(value As String) As YourEnumType
    Return CType(GetEnumByStringValueAttribute(value, GetType(YourEnumType)), YourEnumType)
End Function

And then a call to get the Enum (using string attribute):

Dim mEnum as MyEnum = GetEnumByStringValueAttribute(Of MyEnum)("Personal Contact")

To get the "Attribute" value out (removed handling 'Nothing' for clarity):

  Public Function GetEnumValue(Of YourEnumType)(p As YourEnumType) As String
        Return DirectCast(Attribute.GetCustomAttribute(ForValue(p), GetType(StringValueAttribute)), StringValueAttribute).Value
  End Function

  Private Function ForValue(Of YourEnumType)(p As YourEnumType) As MemberInfo
        Return GetType(YourEnumType).GetField([Enum].GetName(GetType(YourEnumType), p))
  End Function

And the call to get the string attribute (using Enum):

Dim strValue as String = GetEnumValue(Of MyEnum)(MyEnum.Contact)