vb.net – 枚举类型实现位于Class实现的内部或外部

Public Enum vehicleType
    Car
    Lorry
    Bicycle
End Enum
Public Class TrafficSurveyA
    ' Declare the fields here.
    Private fCars As Integer
    Private fBicycles As Integer
    Private fLorries As Integer

    Public Sub New()
        ' An instance of TrafficSurveyA is created with all vehicle counts set to zero.
        fCars = 0
        fBicycles = 0
        fLorries = 0
    End Sub
    Public Sub incrementCount(ByVal vehicle As vehicleType)
        ' Preconditions: none
        ' Postconditions: If vehicle is "Car","Bicycle" or "Lorry" then 1 is added
        ' to the corresponding count. Otherwise nothing is done.

        Select Case vehicle
            Case vehicleType.Car : fCars = fCars + 1
            Case vehicleType.Bicycle : fBicycles = fBicycles + 1
            Case vehicleType.Lorry : fLorries = fLorries + 1
            Case Else 'do nothing
        End Select
    End Sub

    Public Function getCount(ByVal vehicle As vehicleType) As String
        ' Preconditions: none
        ' Postconditions: If vehicle is "Car","Bicycle" or "Lorry",the string
        ' representation of the corresponding count is returned.
        ' Otherwise the empty string is returned.

        Dim result As String
        result = ""
        Select Case vehicle
            Case vehicleType.Car : result = Convert.ToString(fCars)
            Case vehicleType.Bicycle : result = Convert.ToString(fBicycles)
            Case vehicleType.Lorry : result = Convert.ToString(fLorries)
            Case Else : result = ""
        End Select
        Return result
    End Function

    Public ReadOnly Property Vehicles() As String
        ' Preconditions: none
        ' Postconditions: The total number of vehicles recorded is returned.
        Get
            Return (fCars + fBicycles + fLorries).ToString()
        End Get
    End Property
End Class

似乎Enum可以很容易地放在TrafficSurveyA类中,就像这样……

Public Class TrafficSurveyA

    Enum vehicleType
        Car
        Lorry
        Bicycle
    End Enum

    ' Declare the fields here.
    Private fCars As Integer
    Private fBicycles As Integer
    Private fLorries As Integer

    Public Sub New()
        ' An instance of TrafficSurveyA is created with all vehicle counts set to zero.
        fCars = 0
        fBicycles = 0
        fLorries = 0
    End Sub
    ...
    ...

唯一的区别似乎是我需要使用此TrafficSurveyA.vehicleType.Lorry而不是此vehicleType.Lorry的GUI代码.

两者似乎都运行正常,但枚举类型的这些实现之一是错误的吗？