Question

我创建了一个带窗口形式的网站，我只在远程页面中出现System.NullReferenceException错误，如果我尝试用visual studio打开页面，在调试模式下，没有问题！为什么！？！？！？！

[NullReferenceException: Riferimento a un oggetto non impostato su un'istanza di oggetto.]
   GeCo.DetaglioMilitare.Page_Load(Object sender, EventArgs e) in C:\Users\j972537\Documents\
Visual Studio 2010\Projects\GeCo\Admin\DettaglioMilitare.aspx.vb:45
   System.Web.UI.Control.OnLoad(EventArgs e) +92
   System.Web.UI.Control.LoadRecursive() +54
   System.Web.UI.Page.ProcessRequestMain(
     Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +772

这是带错误的代码：

 Dim militare As New ldap.utente
    militare = ldap.ldap_utente(matricola2)


    Label7.Text = militare.grado
    Label8.Text = militare.cognome
    Label9.Text = militare.nome
    Label10.Text = militare.codice_reparto
    Label11.Text = militare.intestazione_reparto
    Label12.Text = militare.email

这是我创建的类模块：

Public Class ldap

Public Class utente

    Private _matricola As String = ""
    Public Property matricola() As String
        Get
            Return _matricola
        End Get
        Set(ByVal val As String)
            _matricola = val
        End Set
    End Property

    Private _grado As String = ""
    Public Property grado() As String
        Get
            Return _grado
        End Get
        Set(ByVal val As String)
            _grado = val
        End Set
    End Property

    Private _cognome As String = ""
    Public Property cognome() As String
        Get
            Return _cognome
        End Get
        Set(ByVal val As String)
            _cognome = val
        End Set
    End Property

    Private _nome As String = ""
    Public Property nome() As String
        Get
            Return _nome
        End Get
        Set(ByVal val As String)
            _nome = val
        End Set
    End Property

    Private _codice_reparto As String = ""
    Public Property codice_reparto() As String
        Get
            Return _codice_reparto
        End Get
        Set(ByVal val As String)
            _codice_reparto = val
        End Set
    End Property

    Private _intestazione_reparto As String = ""
    Public Property intestazione_reparto() As String
        Get
            Return _intestazione_reparto
        End Get
        Set(ByVal val As String)
            _intestazione_reparto = val
        End Set
    End Property

    Private _email As String = ""
    Public Property email() As String
        Get
            Return _email
        End Get
        Set(ByVal val As String)
            _email = val
        End Set
    End Property
End Class



' funzione per estrarre i dati relativi ad una matricola
Public Shared Function ldap_utente(matricola As String) As utente

    Dim directory As DirectoryServices.DirectorySearcher
    Dim result As DirectoryServices.SearchResult

    Dim militare As utente = New utente

    Try
        directory = New DirectoryServices.DirectorySearcher("(cn=" & matricola & ")")
        result = directory.FindOne

        militare.matricola = matricola
        militare.grado = result.Properties("title")(0).ToString
        militare.cognome = result.Properties("sn")(0).ToString
        militare.nome = result.Properties("givenname")(0).ToString
        militare.codice_reparto = Left(result.Properties("physicaldeliveryofficename")(0).ToString, 5)
        Dim lenght_string As Integer = result.Properties("description")(0).ToString.Length
        militare.intestazione_reparto = Trim(Right(result.Properties("description")(0).ToString, lenght_string - 7))
        militare.email = result.Properties("mail")(0).ToString()

        Return militare

    Catch ex As Exception

        Return Nothing

    End Try

End Function

Answer 1

因为你没有包含DettaglioMilitare.aspx.vb:45行的信息，所以我只能诊断可能发生的事情。

在wxception发生时，在函数ldap_utente中，返回与Nothing相同的Null。因此，要调查代码中的错误，您有两种选择：

调试代码以查看您遇到的异常
如果无法进行调试，请在您的代码中添加日志记录，或者抛出此异常以在浏览器窗口中查看它\

我几乎可以肯定您在连接到Active Directory时遇到问题，因为99％的页面安装为无法访问Active Directory的IIS用户。您可以尝试将应用程序池用户更改为域用户。

远程机器上的System.NullReferenceException？

1 个答案: