asp.net - VB.NET Web 服务 - 从继承类返回只读属性

Question

我想我错过了一些非常基本的东西，但这就是我的困境。在 VB.net 中，我创建了一个继承 MembershipUser 并从 Web 服务返回对象的类:

Public Class ModifiedUser
    Inherits MembershipUser

用户登录:

Private Sub Login1_Authenticate(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.AuthenticateEventArgs) Handles Login1.Authenticate
    Dim ws As New MembersWS.Members
    Dim Member As New MembersWS.ModifiedUser
    ws.Credentials = System.Net.CredentialCache.DefaultCredentials()
    Member = ws.ValidateUser(Login1.UserName, Login1.Password)
End Sub

在 Web 服务中创建对象时，ModifiedUser 包含 MembershipUser 的所有属性以及新类的属性。

在我的示例中，ValidateUser 函数验证用户并添加其他属性:

Public Function ValidateUser(ByVal UserName As String, ByVal Password As String) As ModifiedUser
    Dim BaseUser As MembershipUser = Membership.Provider.GetUser(UserName, False)
    Dim Member As New ModifiedUser
    If Membership.Provider.ValidateUser(UserName, Password) = True Then 
        Member = New ModifiedUser(BaseUser.ProviderName, BaseUser.UserName, BaseUser.ProviderUserKey, BaseUser.Email, BaseUser.PasswordQuestion, BaseUser.Comment, BaseUser.IsApproved, BaseUser.IsLockedOut, BaseUser.CreationDate, BaseUser.LastLoginDate, BaseUser.LastActivityDate, BaseUser.LastPasswordChangedDate, BaseUser.LastLockoutDate, 0, "", "", "", "", True)
        ' ... (Set new property values)
    End if
    Return Member
End Function

当 Member 返回到 Login1_Authenticate 时，只读属性将从对象中删除，同时它们包含在从 Web 服务返回的对象中。

在 Web 服务的 reference.vb 文件中，自动生成的代码包含部分 MembershipUser 类，其中仅包含可更新的属性以及关联的 getter 和 setter:

Partial Public Class MembershipUser
    Private emailField As String
    Private commentField As String
    Private isApprovedField As Boolean
    Private lastLoginDateField As Date
    Private lastActivityDateField As Date

如果有人能让我知道如何在返回的对象中包含只读属性，我将非常感激。

Answer 1

当 Web 服务返回包含只读属性的对象时，只读属性始终会被忽略。这是因为在客户端，无法通过设置只读属性的值来反序列化数据。解决此问题的一种方法是向您的属性添加一个 setter ，该 setter 不执行任何操作或引发异常。例如:

Public Property Id() As Integer
    Get
        Return nID
    End Get
    Set(ByVal Value As Integer)
        Throw New Exception("Cannot set read-only property 'Id'")
    End Set
End Property

请参阅此问题以获取更多想法:

Is it possible to create read only elements in SOAP web services?