Web Forms :: Object Reference Error While Rendering Menu Control
Sep 21, 2010
I am having a problem with rendering a menu control inside a server control. I am getting an error in the RenderContents override method when I try to render the Menu Control. The error I am getting is an Object Reference error. The code is below...
I created a custom server control. The control works perfectly when added into a project. The issue I have though, is that in the designer - it shows the error --> "Error creating control - MyControl1 Object Reference not set to an instance of an object" The error is because I am using this code to load startup scripts
Dim pg As Page = HttpContext.Current.Handler
if i comment it out then the designer does not throw the object reference error so I know this is where the problem is. So here is my question: How can I get the designer to ignore the HttpContext.Current.Handler object for rendering puroposes?
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.
I am using grid view as mentioned below, it is giving me error "object reference not set", but if comment allowpaging and pagesize lines, it works. let me know whats wrong I am doing?
I got this error "object reference not set to an instance of an object" when i want to display the values of dynamic generated drop down lists by pressing a button to show the values in Listitem.
i have create dynamic menu control , i have master page and login page , once the user login , i want to show the dynamic menu in my master page. below i try to call masterpage control in my child page ,but i throughs the error
Object reference not set to an instance of an object. my master page code public partial class MasterPage : System.Web.UI.MasterPage { protected void Page_Load(object sender, EventArgs e) { } public string MyProperty { set { // lblUser.Text = value; lblUser.Text = value; // here i got the error } } }
My child page code
protected void btnwork_Click(object sender, EventArgs e) { ((MasterPage)this.Master).MyProperty = "Text changed from Sub Page"; }
I am trying to assign user control from another user control ..first time its binding control successfully but when we refresh the data its giving error
saying "Object reference is not set an instance".
how to refresh data from another user control ...
My senerio below :
1 Aspx page
2. User control
calling usercontrol databinding method from aspx page but once it get refreshed ,not allowed to bind it again..
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?
I'm new to programming in ASP.NET, but I'm making my way through Wrox's Beginning ASP.NET 3.5 in C# and VB.NET.
I'm at a section where I'm creating a BasePage. I successfully created a BasePage by creating a new class file in my App_Code folder called BasePage.cs with the following code:
[Code]....
If I run that code everything works out fine. The page loads and all is well. But, if I try to do the same thing to a page that uses my MasterPage.master file, I get the following error:
Object reference not set to an instance of an object.
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.NullReferenceException: Object reference not set to an instance of an object.
Why is that? In the example code from the book (that also uses a MasterPage.master file), everything excutes and runs just fine. But in my test, I get the above error. I've tried comparing my pages to the books included source pages, but I can't find any differences.
I have just recently converted my VB code to C# and now having this error when I try to add an item to my listbox, and the value is coming from the item page. I get the error at this segement:
lstboxCart.Items.Add(cartItem.Display());
My listbox is supposed to add the product's name, quantity, and price onto one row.
Here's what I have so far:
[code]...
[Code]....
[Code]....
My guess is that the source of the problem could be in the foreach loop from my cart class, shouldn't I be using that for arrays only? If I need to post any markup code or any other class, let me know.
Here I want when click on linkbutton it change text's color so I wrote below code:
protected void c(object sender, EventArgs e) { this.GetCustomersPageWiseMC(1, (sender as LinkButton).CommandArgument); BindDataListD(DLclassC, "classTI_documentry"); DataListItem item = (DataListItem)(sender as LinkButton).NamingContainer; foreach (DataListItem dlItems in DLclass.Items)
[Code] ....
For Linkbtnclass_Click it worked correctly and when I click on linkbutton it change color but for LinkbtnclassC_Click when I click on linkbutton it make this error:
Server Error in '/' Application.
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:
Line 537: { Line 538: LinkButton lb1 = dlItems1.FindControl("Linkbtnclass1") as LinkButton; Line 539: lb1.ForeColor = ColorTranslator.FromHtml("#646464"); Line 540: } Line 541:
In manager.aspx page I have gridview that bind product information from database in this gridview I define linkbutton EDIT that when users click on it they go to Edit.aspx page and in this page users can see their product information and Edit them
In Edit.aspx page I use some textbox and dropdownlist and bind them from database
int data1 = Convert.ToInt32(Request.QueryString["Id"].ToString()); SqlCommand _cmd = new SqlCommand("viewProduct", _cn); _cmd.CommandType = CommandType.StoredProcedure; _cmd.Parameters.AddWithValue("@id", data1); _cn.Open(); SqlDataReader _dr = _cmd.ExecuteReader();
[Code] ....
When I click on EDIt linkbutton from gridview it go to Edit.aspx page and bind all data from database and ofcourse show data in Dropdownlist untill now every thing is ok
but when I change some Item in this page i.e Name of product when I changed and clicked on button to update table in database it update data in database but below error happen too
Server Error in '/behtop website' Application.
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:
Line 79: Line 80: Line 81: DDL1.Items.FindByText(_dr["classification"].ToString()).Selected = true; Line 82: DDL2.Items.FindByText(_dr["subset"].ToString()).Selected = true; Line 83:
And when I back to manager.aspx and again click on Edit linkbutton to Edit that product it didn't load Edit.asp page and above error happen again...
This error happen just when I want edit product information in other time if I don't edit any thing edit.aspx page load successfully...
This might have been asked before but I did a quick search and found nothing.
Problem: I want to get the name of the object that has a value of nothing and the type of the object when the "Object reference not set to an instance of an object error" occurs. The type obviously can be Object or specific. I want this information so that I can log a better error message in the error handling module. The only real useful information currently that comes back from the Exception object on a try catch is the line number at which the error occurred which in most cases is adequate except when you have functions calling functions, all in one line.
why the following code bombs with a NullReference exception.
[Code]....
I just want to output the html for the menu control to a string, if I remove the line that adds the new menu item or I change the control to a calander control instead of a menu control the it works fine.
I'm using asp.net with asp.net configuration and I keep on getting the same error:
"Object reference not set to an instance of an object."
It happens when I'm logged in to the website and i leave a page open for more then 5 minutes without doing anything.. I can't trace it because on debug mode it works fine.. First i thought it might be the session timeout but I've extended it to 60 minutes and still the same error.