Question

I have a bizarre problem. I use a lot of session variables so I don’t have to pass it all back and forth every time a page does a postback. I have been doing this for years so I’m at a complete loss.

I have a file called SessionHandler.vb in the App_Code folder that has the following code:

Imports Microsoft.VisualBasic

Public Class SessionHandler

    Private Shared _chgLinePkNum As String = "0"
    Private Shared _chgStudentIDPk As String = "0"

    Public Shared Property chgLinePkNum() As String
        Get
            ' Check for null first
            If (HttpContext.Current.Session(SessionHandler._chgLinePkNum) Is Nothing) Then
                ' Return an empty string if session variable is null.
                Return "Nothing"
            Else
                Return HttpContext.Current.Session(SessionHandler._chgLinePkNum).ToString()
            End If
        End Get

        Set(ByVal value As String)
            If (value Is Nothing) Or (value = "") Then
                HttpContext.Current.Session(SessionHandler._chgLinePkNum) = "Nothing"
            Else
                HttpContext.Current.Session(SessionHandler._chgLinePkNum) = value
            End If
        End Set
    End Property

    Public Shared Property chgStudentIDPk() As String
        Get
            ' Check for null first
            If (HttpContext.Current.Session(SessionHandler._chgStudentIDPk) Is Nothing) Then
                ' Return an empty string if session variable is null.
                Return "Nothing"
            Else
                Return HttpContext.Current.Session(SessionHandler._chgStudentIDPk).ToString()
            End If
        End Get

        Set(ByVal value As String)
            If (value Is Nothing) Or (value = "") Then
                HttpContext.Current.Session(SessionHandler._chgStudentIDPk) = "Nothing"
            Else
                HttpContext.Current.Session(SessionHandler._chgStudentIDPk) = value
            End If
        End Set
    End Property

Simple enough… Then, in my code, I reference the properties by SessionHandler.chgLinePkNum. This block of code has LineItemNumber = 1 and StudentID = [the actual ID number].

    If IsParking And checkbox.Checked = True Then
        SessionHandler.chgLinePkNum = LineItemNumber
        SessionHandler.chgStudentIDPk = StudentID
        peParkingRegistration.Show()
    End If

When the first line runs, chgLinePkNum is set to 1 as expected. For some strange reason, it is also setting chgStudentIDPk to 1. When the next line is run, it sets chgStudentIDPk to the correct StudentID number. The problem is, it also sets chgLinePkNum to the StudentID number.

I have run it line by line in the debugger and each property set function runs only when it is called. I just can’t figure out how “HttpContext.Current.Session(SessionHandler._chgLinePkNum) = value” is setting the value for chgStudentIDPk and vice versa.

Answer 1

Anything to do with these having the exact same value?

Private Shared _chgLinePkNum As String = "0"
Private Shared _chgStudentIDPk As String = "0"