C# - Session Variable Assigned To Data Table And Create Object Reference?
Jan 13, 2010
----> I have datatable which is passing to another page in session variable.
----> Now on another page i take the session variable into datatable.
datatable ds_table = new datatable();
ds_table = (datatable)session["table_value"];
----> so problem, is that , when i filtering some rows from ds_table . that taking effect in the session variable. if some rows deleted from ds_table. then it is also deleted from session variable.
----> so, anyone tell me why is this going to happene?
xamount is receiving this message on the last line. The session is being set in the previous page. Is there a way to resolve the message or should I just use a previous page postback
I am declaring a list in my class, populating the list in page load and using the list in various methods in this class. But, I get this error at every instance where I use this list in the methods. Error: System.NullReferenceException: Object reference not set to an instance of an object.
In the VS2005 environment, when I test my session to make sure the page redirects to the main page (itself) if the session is null, it works. There is no error.
The function I use for this is:
[code]....
However, when it is in the production environment in IIS 6.0, when the session has timed out, and I then do a postback by doing some slider control, I see the page reload but immediately thereafter, it throws a Server Error exception of : Object reference not set to an instance of object.
however, why is it that the Slider1_TextChanged event fired even even after during page_load, the page was told to do a response.direct ?? shouldn't the entire page have gone through a full-page refresh life cycle ? why did it continue on to attempt to raise the Slider1_TextChanged event?
For some unknown reason I suddenly am unable to create an object variable for a Linq Data Class. If I create a new project and try the process again with the same database everything works as advertized.The code I am using is Dim db As New RoggDataContext which gives me an error on the object variable "db": Overload resolution failed because no accessibility 'NEW' accepts this number of arguments.I have looked inside every file in the Web Project like the web config to check the connection string, gobal, and designer.vb looking for any errors whit no JOY. I also tried to create a new form and code behind with a button and received the same error.This is mind blowing because as I already stated, I can create a new Web Site and the problem goes away.
I searched on this all morning, but I'm still not sure. If I create a session variable to pass some data between a couple of pages, does that variable time out after it reaches the timeout period set on IIS, or will it persist for the entire time the user keeps a session alive? For example, session variable is used shortly after login and then never again. Susy uses other pages for two hours and keeps session active. Did that first session variable die after 20 minutes, or is it still there 2 hours later?
I am facing a very strange issue. I get an error Object Reference Not set to instance of object on the server while the code runs fine on my dev machine. The strange part is the line number where the code is throwing error (as appears in the Stack trace)
When i press the delete button, everything works fine and the folder gets deleted. but after that when page postbacks again then a NullRefrenceException is raised at Label1.Text = Session["loginid"].ToString(); why is it happening...?? When I am not using this Directory.Delete() method everything is working fine and session variables are not set to null. When I traced my application I found that After Directory.Delete() method Session variables were intact and I was able to use those session variables in the processing after Directory.Delete(). But as soon as the page postbacks all session variables are set to null. And this problem doesn't appear when i m not using this delete() method. The folder I m deleting is in my project's folder. I m running this website using Visual Studio.
I am getting thid error Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.NullReferenceException: Object reference not set to an instance of an object. Source Error:
I noticed that when i am debugging my web application in Visual Studio 2005 using IIS, after about 10-15 minutes of inactivity, when I do something in the application such as a postback, I get an immediate error saying: "object reference not set to an instance" and my code breaks somewhere.Is my assumption correct that this is because my session has timed out? ( i do have a 15 minute default session time)my next question is, how do I display or set a way so that like many other pages, when the session has expired, a message will say: "This page must be refreshed" or "Your session has expired, click okay to refresh page" and start over again?
in my default.aspx page i have a dropdown List and a textbox with a submit button below that there are 2 listbox... and the dropdown list holds the names of the listbox
my logic here is to select an item from the dropdown list and put some text in the text box and submit the form which will add an item to the listbox selected.. but when i do this i get an error saying Object reference not set to an instance of an object. i tried to figure out the problem and found that when i remove the reference to the Site Master Page it works fine and when i undo and apply my reference back to the Site Master Page i get the same error.
The line "Return strLoc" below shows the green line underneath strLoc with the message "Variable 'strLoc' used before it has been assigned a value." In fact, it returns the value just fine to the calling module, so I'm wondering why it's giving this message and how to prevent it.
I am trying to access a user's login credentials to find out if they are an admin user or not. This way I can assign session variables to them and show certain aspects of the web page that other users won't see. I unfortunately keep getting this error when trying to dim a variable to assign the values too.
Variable Nuid is used before being assigned a value. Variable AdminUser is used before being assigned a value.
Code: Protected Sub checkAdmin_Click(sender As Object, e As EventArgs) Handles checkAdmin.Click Dim strNuid As String = Request.Form("Nuid") Dim cnString As String = ConfigurationManager.ConnectionStrings("snfTimeSystemConnectionString").ToString() Try Using cn As SqlConnection = New SqlConnection() cn.ConnectionString = cnString
I was working on my homework, making a website obiously, but I have a small problem with the griedview. I wanted to add a button on the end of the row, but I receive some error notifications and warnings too...
SeverityCodeDescriptionProjectFileLineSuppression State ErrorBC30518Overload resolution failed because no accessible 'Add' can be called with these arguments: 'Public Overloads Sub Add(column As DataColumn)': Value of type 'ButtonField' cannot be converted to 'DataColumn'. 'Public Overloads Function Add(columnName As String) As DataColumn': Value of type 'ButtonField' cannot be converted to 'String'.GIPH:GIPSearch.aspx.vb31Active
Can I set up an ASP.Net datasource in the ASPX code as opposed to the code behind) where the datasource is a DataTable that's stored in a Session variable?
I'm pretty new to silverlight and asp.net but I have a strong background in c#. I am currently developing a c# asp.net application with silverlight elements. I was wondering if it was possible to have a user say click on an image that has a certain value associated with it and have that value access from a c# variable held outside the silverlight application.
Why do we use the reference of abstract class (or base class) to create object of it's sub-class. eg: TextWriter is the abstract class for StreamWriter & StreamWriter.
I'm fairly new to ASP.net development as may have been noticed by some of my other posts and so here goes another one.I have a web page in which I allow users to enter data that will be used to populate a database and then graph data based on the information that was saved in the database. I have 10 sets of criteria that the user can enter and as they enter values for each individual set, I make sure all the parameters are filled in and set a variable called blnParm1, blnParm2, blnParm3, etc. Anyway, as each DropDownList box fires off an event the values of my blnParm variables is reset because each time the event is fired the page is PostBack therefore my variables are redeclared. I know the page is being PostBack because each of the DropDownList boxes have AutoPostBack set to true. I had to do this so that I could get the OnSelectedIndexChanged event to fire for each of the DropDownList boxes. So, how do I preserve my variables through this PostBack or how do I get the events to trigger without calling AutoPostBack?
Some more info, my variables are declared globally in my aspx.cs file as private bool. The code is working like it should as far as populating drop downs dynamically based on other data input by the user, the controls all have their values preserved as the page is PostBack.
I have a publice variable to be used in the same webpage. when the user click on button 1, it does some process and assign a value to my public variable. After that, the user can click on button 2 which needs the public variable value to function. However I see the value of the public variable is 0 when I click on button 2.
I'm building an application using MVC3 RC and I'm trying to add a session variable as soon as anyone logs on. The variable is an int which is retrieved from a database using User.Identity.Name to retrieve the relevant database record.
I'm using the MS AccountController and tried adding the session variable immediately after the line:
