rss2
asked on
VB.NET scope of property values
I am using properties in vb.net for an asp.net web site.
On the firstpage.aspx, I'm setting the username variable. When the submit button is clicked, I'm getting the value and passing it into a stored procedure.
I seem to lose that value that I just set, and I suspect it has to do with where I'm declaring a reference to the class where the properties are set incorrectly.
Here's my code: In LoadData() the value strGroup_Name is Nothing.
Imports System.Text
Imports System.Data
Imports System.Collections
Imports System.Data.SqlClient
Imports System.DirectoryServices
Partial Class Homepage
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim sv As New SetVars
If Not IsPostBack Then
sv.strGroup_Name = "UK-GLBL-xxxxxxx" ' Will get from Active Directory
sv.strUser_Name = "MEADWAYP" 'Request.ServerVariables("
GetPermissions(sv.strGroup
LoadData()
End If
End Sub
Protected Sub LoadData()
Dim conn As New SqlConnection
Dim cmd As New SqlCommand
Dim connstring As String
Dim da As New SqlDataAdapter
Dim dt As New DataTable
Dim sv As New SetVars
connstring = Connector.ConnectStringBui
conn.ConnectionString = connstring
cmd.Connection = conn
cmd.CommandText = "ACT_GET_HOMEPAGE_DETAILS"
cmd.CommandType = CommandType.StoredProcedur
cmd.Parameters.Add("@GROUP
conn.Open()
da.Fill(dt)
Me.Repeater1.DataSource = dt
Me.Repeater1.DataBind()
'cmd.ExecuteNonQuery()
conn.Close()
conn = Nothing
cmd = Nothing
End Sub
Why isn't it set?
Thanks,
rss2
On the firstpage.aspx, I'm setting the username variable. When the submit button is clicked, I'm getting the value and passing it into a stored procedure.
I seem to lose that value that I just set, and I suspect it has to do with where I'm declaring a reference to the class where the properties are set incorrectly.
Here's my code: In LoadData() the value strGroup_Name is Nothing.
Imports System.Text
Imports System.Data
Imports System.Collections
Imports System.Data.SqlClient
Imports System.DirectoryServices
Partial Class Homepage
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim sv As New SetVars
If Not IsPostBack Then
sv.strGroup_Name = "UK-GLBL-xxxxxxx" ' Will get from Active Directory
sv.strUser_Name = "MEADWAYP" 'Request.ServerVariables("
GetPermissions(sv.strGroup
LoadData()
End If
End Sub
Protected Sub LoadData()
Dim conn As New SqlConnection
Dim cmd As New SqlCommand
Dim connstring As String
Dim da As New SqlDataAdapter
Dim dt As New DataTable
Dim sv As New SetVars
connstring = Connector.ConnectStringBui
conn.ConnectionString = connstring
cmd.Connection = conn
cmd.CommandText = "ACT_GET_HOMEPAGE_DETAILS"
cmd.CommandType = CommandType.StoredProcedur
cmd.Parameters.Add("@GROUP
conn.Open()
da.Fill(dt)
Me.Repeater1.DataSource = dt
Me.Repeater1.DataBind()
'cmd.ExecuteNonQuery()
conn.Close()
conn = Nothing
cmd = Nothing
End Sub
Why isn't it set?
Thanks,
rss2
dctuck
On every Page_Load, you're setting sv to be a brand new SetVars class. Perhaps moving this inside the Not IsPostback code would work?
It needs to be private to the class, not to the page_load event handler:
Imports System.Text
Imports System.Data
Imports System.Collections
Imports System.Data.SqlClient
Imports System.DirectoryServices
Partial Class Homepage
Inherits System.Web.UI.Page
#Region "Declarations"
Private sv As SetVars 'Declare the object here with scope for the whole class
# End Region
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
sv = New SetVars 'Instantiate the object here
If Not IsPostBack Then
sv.strGroup_Name = "UK-GLBL-xxxxxxx" ' Will get from Active Directory
sv.strUser_Name = "MEADWAYP" 'Request.ServerVariables("
GetPermissions(sv.strGroup
LoadData()
End If
End Sub
And so on.
Imports System.Text
Imports System.Data
Imports System.Collections
Imports System.Data.SqlClient
Imports System.DirectoryServices
Partial Class Homepage
Inherits System.Web.UI.Page
#Region "Declarations"
Private sv As SetVars 'Declare the object here with scope for the whole class
# End Region
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
sv = New SetVars 'Instantiate the object here
If Not IsPostBack Then
sv.strGroup_Name = "UK-GLBL-xxxxxxx" ' Will get from Active Directory
sv.strUser_Name = "MEADWAYP" 'Request.ServerVariables("
GetPermissions(sv.strGroup
LoadData()
End If
End Sub
And so on.
ASKER
Ok, thank you.
And what about in the other aspx.vb modules?
How so I instantiate the SetVars class without overwriting the previously set values?
Do I:
Partial Class Collections
Inhereits System.Web.UI.Page
Private sv as New SetVars
?
And what about in the other aspx.vb modules?
How so I instantiate the SetVars class without overwriting the previously set values?
Do I:
Partial Class Collections
Inhereits System.Web.UI.Page
Private sv as New SetVars
?
Does setVars class then need to be a public shared class amongst your application? If so then you would be better off perhaps creating it as a module and having Shared Property access to its properties and methods. This way you can have a single instance of the class but all your pages can access the same instance.
ASKER
Yes, that is what I intend to do...to have the one class and reference it from all other classes in the application. Must it have "shared properties" to do that?
How do I reference the module SetVars throughout the application?
Dim sv as SetVars?
Dim sv as New Setvars?
Also when I make the properties within SetVars shared, I get blue squiggly lines everywhere.. The error message says: "Cann refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class."
Here is the SetVars code below:
Imports Microsoft.VisualBasic
Imports System
Public Class SetVars
Public strIndicator As String
Public iService_ID As Integer
Public strUser_Name As String
Public strGroup_Name As String
Public strUser_Greeting As String
Public Shared Property UserGreeting() As String
Get
UserGreeting = strUser_Greeting
End Get
Set(ByVal value As String)
strUser_Greeting = value
End Set
End Property
Public Shared Property Indicator() As String
Get
Indicator = strIndicator
End Get
Set(ByVal value As String)
strIndicator = value
End Set
End Property
Public Shared Property Service_ID() As String
Get
Service_ID = iService_ID
End Get
Set(ByVal value As String)
iService_ID = value
End Set
End Property
Public Shared Property UserName() As String
Get
UserName = strUser_Name
End Get
Set(ByVal value As String)
strUser_Name = value
End Set
End Property
Public Shared Property GroupName() As String
Get
GroupName = strGroup_Name
End Get
Set(ByVal value As String)
strGroup_Name = value
End Set
End Property
End Class
How do I reference the module SetVars throughout the application?
Dim sv as SetVars?
Dim sv as New Setvars?
Also when I make the properties within SetVars shared, I get blue squiggly lines everywhere.. The error message says: "Cann refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class."
Here is the SetVars code below:
Imports Microsoft.VisualBasic
Imports System
Public Class SetVars
Public strIndicator As String
Public iService_ID As Integer
Public strUser_Name As String
Public strGroup_Name As String
Public strUser_Greeting As String
Public Shared Property UserGreeting() As String
Get
UserGreeting = strUser_Greeting
End Get
Set(ByVal value As String)
strUser_Greeting = value
End Set
End Property
Public Shared Property Indicator() As String
Get
Indicator = strIndicator
End Get
Set(ByVal value As String)
strIndicator = value
End Set
End Property
Public Shared Property Service_ID() As String
Get
Service_ID = iService_ID
End Get
Set(ByVal value As String)
iService_ID = value
End Set
End Property
Public Shared Property UserName() As String
Get
UserName = strUser_Name
End Get
Set(ByVal value As String)
strUser_Name = value
End Set
End Property
Public Shared Property GroupName() As String
Get
GroupName = strGroup_Name
End Get
Set(ByVal value As String)
strGroup_Name = value
End Set
End Property
End Class
ASKER
Sorry that "Cann" should read "Cannot"
Private Shared strIndicator As String
Private Shared iService_ID As Integer
Private Shared strUser_Name As String
Private Shared strGroup_Name As String
Private Shared strUser_Greeting As String
These need to be declared as shared variables also.
They don't need to be public because you will only be accessing them through your properties so the actual value can be private to the class but must be declared as shared still so that the shared properties can access the variables.
Private Shared iService_ID As Integer
Private Shared strUser_Name As String
Private Shared strGroup_Name As String
Private Shared strUser_Greeting As String
These need to be declared as shared variables also.
They don't need to be public because you will only be accessing them through your properties so the actual value can be private to the class but must be declared as shared still so that the shared properties can access the variables.
ASKER
Great. Thank you.
Within the aspx.vb classes, how to I instantiate the SetVars class to get to its properties?
For example, in my firstpage.aspx.vb I get blue squiggly lines underneath "sv.strUser_Greeting":
Imports System
Imports System.Text
Imports System.Data
Imports System.Collections
Imports System.Data.SqlClient
Imports System.DirectoryServices
Partial Class Collections
Inherits System.Web.UI.Page
Dim sv As SetVars
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
'Display the correct controls according to the group's permissions
Me.lblUserGreeting.Text = sv.strUser_Greeting
LoadData()
End Sub
?
Within the aspx.vb classes, how to I instantiate the SetVars class to get to its properties?
For example, in my firstpage.aspx.vb I get blue squiggly lines underneath "sv.strUser_Greeting":
Imports System
Imports System.Text
Imports System.Data
Imports System.Collections
Imports System.Data.SqlClient
Imports System.DirectoryServices
Partial Class Collections
Inherits System.Web.UI.Page
Dim sv As SetVars
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
'Display the correct controls according to the group's permissions
Me.lblUserGreeting.Text = sv.strUser_Greeting
LoadData()
End Sub
?
ASKER
Sorry, I'm an idiot.
I changed the line to "sv.UserGreeting" and that removed the blue squiggly line. But now I get a green one. (think I'll just go through all the colours of the spectrum while I'm at it..)
Anyway, the error is "Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated."
??
I changed the line to "sv.UserGreeting" and that removed the blue squiggly line. But now I get a green one. (think I'll just go through all the colours of the spectrum while I'm at it..)
Anyway, the error is "Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated."
??
ASKER CERTIFIED SOLUTION
membership
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ASKER
Awesome. You truly are a GENIUS.
thank you! :)
thank you! :)