In ASP.NET/VB.NET 2005 I've created a small web app with two forms.
In Default there is a button and a text box and a link.
When you press the button whatever is in the text box is put into the Session. [code]....
In the Session_Start of the Global.asax i have
Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)
Session("login") = False
[code]....
Why i am getting error the error Object reference not set to an instance of an object. at line
If Current.Session("login") Is Nothing Then
while checking for the login state as follows?
If GetLogin = False Then
'Do something
End if
I mean i have already created the instance on the Session_Start... Haven't i?
Object reference not set to an instance of an object.[code]Now I currently have no session set on this page. So the session is NULL but i am just wondering why my if statement is taking care of this problem, why does it even try to get to the next part i.e. Response.Write ?
View 3 RepliesStructure MainStruct
Dim Ans1 As String
Dim Ans2 As String
End Structure
[code]....
The question is how can i read back the contents of the list, stored in the Session?I mean something like...
Build = Session("MyData")
How can I access the values stored in a session object with a class in asp.net?
View 3 RepliesSo In Default.master.cs PageLoad I have the following[code]...
However this is causing the following exception!object reference not set to an instance of an object.
What is the best way to provide strongly typed access to the session object? I am planning on turning on Option Strict, which is causing the compiler to complain about my lazy programming technique of directly accessing the session object:
Dim blah As Integer = Session("Blah")
My initial thought is to create a class that wraps the session and provides strongly typed properties for the information stored in the session. However, I cannot decide if the class should be a singleton, or instantiated on every use, or where the code should reside (i.e. within the web project or within a class library).
I'm leaning towards a singleton in my class library, but I don't know if that is the best solution, or if I am missing any other possibilities.
Proposed Solution:
Public Class SessionAccess
Public Shared Property Blah(ByVal session As HttpSessionState) As Integer
Get
[Code].....
I have a VB.NET application which runs perfectly with local host. But when I upload it to my server the session objects throw null reference exception.
Sessions is not working in a single page. If I use session on any other page it is working perfectly.
I have enabled session in that page using the EnableSessionState property. Also in web.config I enabled the use of session variables.
I am storing an array of a custom serializable class in session on my site. When a page on the site changes, suddenly it renders them invalid, and tells me that it can't cast the type to it's own type. I assume the class version numbers are changing or something?!
I'm not trying to redesign this whole process.
Unable to cast object of type 'ShipmentPackages[]' to type 'ShipmentPackages[]'.
Description: An unhandled exception occurred during the execution of the current web request. review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.InvalidCastException: Unable to cast object of type 'ShipmentPackages[]' to type 'ShipmentPackages[]'.
[Code].....
I'm having problem regarding session items. Before I use them, I want to check if they exists, but using this codes gives me error:[code]I think Session("SomeSessionItem") tries to acquire the value of the session item. If the item doesn't exists then it throws exception. But how do I check if a session item exists before using them? I have a page Home.aspx.In the Home.aspx.vb, I instantiate a WebUserControl SomeControl.ascx. Note that in Home.aspx.vb event handler Page_Load I can use a condition to check session without getting an exception.Inside SomeControl.ascx.vb I'm trying to access the session, here's where the exception occurs.
View 5 RepliesI am storing a session variable that a user types into a textbox. With their valid input, their session gets created and they get a little more functionality than the regular end users of the site.I was wondering if it is possible to find a way to add someone's session variable to the end of a URL. This way we can email a link to one of our clients, they click it, and their session has automatically begun. They already have the textbox to enter their code into, but I was told that it would be much easier for the users to just click a link that will start their session.
View 1 RepliesOn startup of my software which i developed in vb.net, it connects to mssql server. I want to have session id or session number of the connection with mssql. I'm sure it is unique number and i want to use this session in my software for different purposes. My question is
1. is there anything like session id or session unique number when you connection mssql server
2. if yes to 1 then how i can get it in vb
I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj
Inherits baseObj
Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
I'm trying to do an scrape a web page but in order to Post the data I need a web session ID like
web_session=HQJ3G1GPAAHRZGFR
How can I get that ID?
My code so far is:
[Code]....
I have a page, a session starts on page load (using global.asax) the user may not move from (or interact with) that page for a long while and I dont want to increase the session timeout. When the session times out after say.. 20 minutes, I want to start a new one, without moving from the page. I also don't want constant keep-alives i want to do it via another method (timer, button press...)
View 1 RepliesPartial Class Preferences_MyPreferences
Inherits System.Web.UI.Page
Dim userID As String = Session("UserID")
This is just a page in asp.net. I want to be able to grab the Session("UserID") but every time I try, I get this error:
Session state can only be used when enableSessionState is set to true, either in a configuration file or in the Page directive. Please also make sure that System.Web.SessionStateModule or a custom session state module is included in the \ section in the application configuration.
If I put that Dim userID inside say the Page_Load Event, then it works fine. Why does it have to be inside an event? I want to dim it once, and use it throughout the page.
I have an 2-d arraylist with 2 fixed columns and dynamic rows. The arraylist will be assigned to the session variable at the end of the code below. My question is how can loop thorugh the arraylist from the session to get its value?
If .SQLDS.Tables(.sSQLDSTbl).Rows.Count > 0 Then
Dim NoOfAdjType(1, .SQLDS.Tables(.sSQLDSTbl).Rows.Count - 1)
For iRow As Integer = 0 To .SQLDS.Tables(.sSQLDSTbl).Rows.Count - 1
[Code].....
We have implemented exam on a single page and store the option in view state as users selects the same. On select of next question page is loaded again. Sometime "If Session("User") = """ turns out true and user logs out.I did setup session on first time page load as
Session.Timeout = 340
Also in web config file session timeout is 2 hours.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Session("User") = "" Then
Response.Redirect("Default.aspx")
[code]....
Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If IsPostBack = True Then
[code]....
Three buttons-ABC,CBA and Show. if you click on ABC and then Click on Show button The textbox shows "ABC" but when I Clicking on CBA button And then Click on Show button The textbox shows again "ABC". IsPostback property will true on each time the page is posted to the server. So the session reset the value.
I have an ASP.NET application that I am developing. I'm using session variables within the app.In Firefox & Chrome, they all work.But in IE (ver 9), there's one variable that's not working. I'm not sure if it's a storage or a retrieval (or both) at this point. The variable in question that I'm storing is a List(T) type. It's the only one of it's kind that I'm using. Can't help but think there's a correlation there.One other old post mentioned the possibility that cache is causing the problem, but I didn't understand the answer very well.
Dim Rec_IDs As New List(Of String)
Rec_IDs = Session("Rec_IDs")
and
Dim Rec_IDs As New List(Of String)
[code].....
As in the title, How to get the session value from asp.net web-service ?
View 1 RepliesI still new using Asp.net with vb.net
Protected Sub login_Click(ByVal sender As Object, ByVal e As EventArgs) Handles login.Click
Dim querystrings As String = "Select Email, Password ,Roles, Nama_Depan, Nama_Belakang from Employee where Email = @email;"
[code]....
how to POST to a php file form a vb.net app: http:[url].... So now I've logged in the user user by posting their username and password to the php file, the php file then does security/checks they exist/etc and if both username and password are correct is stores the user ID in a session variable.Now if the vb.net app tries to download data off a page which needs the user to logged in, it checks this by doing:
if (!isset($_SESSION['uid'])) {
header("Location: index.php");
}
However after having logged correctly in the app the session variable is not set.How does session work with a vb.net app like this?When the user logs in successfully should I download the user id and keep it in the vb.net app and then post it to each page that requires authentication?
I am using visual basic ADO reference to connect to Teradata database. In the code I hold the metadata in the volatile table, However after fixed number of SQL execution statements the session changes thus erasing all the data of the previous session stored as volatile tables. Is there a way to keep the session same during the execution of the code.
View 1 RepliesAm having a problem with session id. I wanna know if it is possible to restart the session id with vb.net... lets say...enter a web application and my
[Code]...
I have written a page with an iFrame that basically cycles through a series of internal pages on our server displaying daily activity for our company. The problem I think is that it sporadically loses its session and redirects back to the login screen to keep losing its session which is the default behavior for anyone on our site trying to access a webpage without being logged in.
I have set the session timeout to 4hrs, the iframe cycles through 6 pages anywhere from 10 seconds to 5 minutes on each, and I have even set the META refresh on the page to refresh every 3 hours. I don't understand what else could possibly stop this page from staying active.
I have an aspx page with a button, the user clicks the button a session variable gets set, I then read the session variable later. here is an exaple of my button:
<
td style="width: 100px" align="center">
<asp:Button ID="btnCiv" runat="server" Height="32px" Width="50px" Font-Bold="true"
[code].....
Everybody seems to come up empty after the initial setting of data.
I programmed my website using visual basic code (via microsoft expression web) and need to post information to a remote location using a php page. How do I take variables from my visual basic code and transfer them to my php code? I was thinking sessions would work, but I haven't figured it out yet.
View 7 RepliesI am building a User Management section to a website CMS.The user has a list of users and then clicks the edit button, the system then stored the UserId in a session and goes to the editUser.aspx page which will show the users details.To get the users details I need to convert the UserId session to a Guid so i can get user details.
I keep getting error message:
System.InvalidCastException: Specified cast is not valid.
Dim selectedUserId As Guid = CType(Session("strUserId"), Guid)
Dim mu As MembershipUser = Membership.GetUser(selectedUserId)
I like to create a session value that expires in 5 minutes.How to do that, do I need to manually compare creation time when I read it?
Session("sessionval") = myvariable
Session("sessioncreated") = now
