我一直在努力，因为我需要访问不在默认UserPrincipal的一部分AD用户属性来扩展在VS 2010 VB应用程序的s.ds.am.UserPrincipal类。 这是一个全新的概念对我来说，我发现这里上一些有用的代码很好，但我有我的扩展，我似乎无法找出碰到2个问题。
问题1：当我试图用我的UserPrincipalEx检索我收到以下错误的用户。
错误：
Principal objects of type MyApp.UserPrincipalEx can not be used in a query against this store
代码将生成错误：
Dim ctx As New PrincipalContext(ContextType.Domain, DomainController)
Dim user As UserPrincipalEx = UserPrincipalEx.FindByIdentity(ctx, samAccountName)
问题2：当我试图创建与我UserPrincipalEx新用户收到以下错误。 当我跟踪PrincipalContext（CTX）入类似乎从网域控制器断开连接。
错误：
Unknown error (0x80005000)
代码将生成错误：
Dim ctx As New PrincipalContext(ContextType.Domain, DomainController, DirectoryOU)
Dim NewADUser As New UserPrincipalEx(ctx, newsamAccountName, newPassword, True)
类：
Imports System.DirectoryServices.AccountManagement
Public Class UserPrincipalEx
Inherits UserPrincipal
Public Sub New(ByVal context As PrincipalContext)
MyBase.New(context)
End Sub
Public Sub New(ByVal context As PrincipalContext, ByVal samAccountName As String, ByVal password As String, ByVal enabled As Boolean)
MyBase.New(context, samAccountName, password, enabled)
End Sub
<DirectoryProperty("Title")> _
Public Property Title() As String
Get
If ExtensionGet("title").Length <> 1 Then
Return Nothing
End If
Return DirectCast(ExtensionGet("title")(0), String)
End Get
Set(ByVal value As String)
Me.ExtensionSet("title", value)
End Set
End Property
<DirectoryProperty("physicalDeliveryOfficeName")> _
Public Property physicalDeliveryOfficeName() As String
Get
If ExtensionGet("physicalDeliveryOfficeName").Length <> 1 Then
Return Nothing
End If
Return DirectCast(ExtensionGet("physicalDeliveryOfficeName")(0), String)
End Get
Set(ByVal value As String)
Me.ExtensionSet("physicalDeliveryOfficeName", value)
End Set
End Property
<DirectoryProperty("Company")> _
Public Property Company() As String
Get
If ExtensionGet("company").Length <> 1 Then
Return Nothing
End If
Return DirectCast(ExtensionGet("company")(0), String)
End Get
Set(ByVal value As String)
Me.ExtensionSet("company", value)
End Set
End Property
' Implement the overloaded search method FindByIdentity.
Public Shared Shadows Function FindByIdentity(ByVal context As PrincipalContext, ByVal identityValue As String) As UserPrincipalEx
Return DirectCast(FindByIdentityWithType(context, GetType(UserPrincipalEx), identityValue), UserPrincipalEx)
End Function
' Implement the overloaded search method FindByIdentity.
Public Shared Shadows Function FindByIdentity(ByVal context As PrincipalContext, ByVal identityType As IdentityType, ByVal identityValue As String) As UserPrincipalEx
Return DirectCast(FindByIdentityWithType(context, GetType(UserPrincipalEx), identityType, identityValue), UserPrincipalEx)
End Function
End Class
