Every thing is fine but when I execute the project, NO control on my user control gets "instantiated" and thus I receive error "Object Reference Not Set"
Note that My Control has,
1) Public property PublicProperty as String
2) 1 Label control
In Load Event Handler I am setting Text property of Label Control to PublicProperty. Here object reference NOT set error occurs (which means Label control is NOT initialized).I don't want to register my control using Src, TagPrefix etc.
I'm having some difficulties registering a custom control from a class library in my webapplication's web.config file (or directly on a single page at all). These are the steps I've taken thus far:
1. I have a class library that generates a dll called "Core" and my webapplication has a reference to this "Core" assembly.
2. The Core class library contains a class called AjaxTable which is of namespace "Core.Presentation.DataViews".
3. AjaxTable extends System.Web.UI.Control.
4. I have added the following to my webapplication's web.config file.
I have adeed a dll file on my project and it's working fine with local system. but when i uploaded it on hosting webspace it's displaying error. "assembly refference is missing" i have alreday added bin folder there. So how to add bin folder on hosting spaces.
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 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?
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 have the following code on RowDataBound my gridview:
If (e.Row.RowType = DataControlRowType.DataRow) Then e.Row.Attributes.Add("onkeydown", "javascript:ChangeRowColor('" & e.Row.ClientID & "')") e.Row.Attributes.Add("onkeyup", "javascript:ChangeRowColor('" & e.Row.ClientID & "')") e.Row.Attributes.Add("onclick", "javascript:ChangeRowColor('" & e.Row.ClientID & "')") Dim lbl As Label = CType(e.Row.FindControl("BOD_NPRGSTA"), Label) lbl.Attributes("onclick") = Page.ClientScript.GetPostBackClientHyperlink(GridView1, "Select$" & e.Row.RowIndex) End If
I would use it to intercept the click on the row of GridView when I click on the Label lbl.The problem I have because when I click on the same label me "smashing" the gridview itself. (He added a blank row for no reason).
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?
Can you tell me how it is better to load classes from the same assembly for multiple times? I will explain:
I have a usercontrol that loads the class from assembly A.DLL using (MyAbstractClass)Assembly.Load(path).CreateInstance(type) each time requested page loads. The control can appear on the page many times (about 20-30) and each of them can load the different type from A.DLL...so if control exists on page 20 times, 20 times (MyAbstractClass)Assembly.Load(path).CreateInstance(type) has been executed.
The question is performance...
Does ASP.NET caches DLLs already loaded dynamically? After first (MyAbstractClass)Assembly.Load(path).CreateInstance(type)and first IO, will ASP.NET load A.DLL from cache on other executions ? Or I need to implement some kind of assemblies caching myself?
If I need to implement caching myself, what is the best and fastest way to do it?
I am attempting to register my user controls within the webconfig file because I am receiving the Element does not exist error, but I am receiving the following error when I try to register them in webconfig:
Invalid or missing attributes found in the tagPrefix entry. For user control, you must also specify 'tagName' and 'src'. For custom control, you must also specify 'namespace', and optionally 'assembly'
The following is the code within the webconfig file:
I'm getting the old "Object reference not set to an instance of an object" error on this code:
nonqueryCommand.Parameters.Add("@comment", SqlDbType.VarChar, 500) nonqueryCommand.Parameters("@comment").Value = CType(FormView1.Row.FindControl("CommentsLabel"), TextBox).Text "CommentsLabel" is a textbox, despite it's name (and I've tried the CTYPE ot Label too).
I receive the following error in the code below: System.NullReferenceException: Object reference not set to an instance of an object. When I am logged into the page I do not receive the error. My Code:
Partial Class _Default Inherits System.Web.UI.Page Protected Sub SqlDataSource4_Selecting(ByVal sender As Object, ByVal e As SqlDataSourceCommandEventArgs) Handles SqlDataSource4.Selecting Dim MemUser As MembershipUser MemUser = Membership.GetUser() UserID.Text = MemUser.ProviderUserKey.ToString() e.Command.Parameters("@UserId").Value = MemUser.ProviderUserKey.ToString() End Sub End Class
I read the following online: You are trying to use a reference variable who's value is Nothing/null. When the value is Nothing/null for the reference variable, that means it is not actually holding a reference to an instance of any object that exists on the heap. You either never assigned something to the variable, never created an instance of the value assigned to the variable, or you set the variable equal to Nothing/null manually, or you called a function that set the variableto Nothing/null for you. The following is the Arthur's code example and his suggested fix which I am sure is right:
Private Sub TestString() Dim a As String If a.Length = 0 Then Console.Write("Yes") End If End Sub
I have a WebUserControl, let's call it "BaseControl.ascx" that acts as a base control for a custom control (a class that inherits BaseControl). Inside BaseControl I have a couple of regular controls (for example a DropDownList called 'dropdown'), which I try to populate in the inheriting control:
csharp Code: namespace ProjectName.Controls{ public class SpecializedControl : BaseControl { public void SetupList() { dropdown.DataSource = "ABCDEFG".ToCharArray(); dropdown.DataBind(); } }}
As far as I know, the only way to register a custom control (eg, not a .ascx control but a class inheriting a control) is to use this syntax on the page:
However, when I now call the 'SetupList' method on this control, from the Page_Load event, it seems that 'dropdown' (the DropDownList control in BaseControl.ascx) is null, it seems it is never instantiated.
To test what is happening I just created a simple TestControl.ascx (note: an ascx file again, so a WebUserControl and not a custom control), also with a dropdown and the same SetupList method.
When I register this control using the following syntax, everything works fine:
In this test case I can choose which syntax to use, but in my actual case I can't. The control I want to put on my page is not an ascx file, it's a class that inherits another control (a custom control), so as far as I know I am stuck with this second syntax. So, I cannot get this to work...
I also tried creating the control dynamically using LoadControl, but that gives the same problem.
Long story short: it seems like I have to use the first syntax to register a control (with a 'Src' tag pointing to the control ascx file), but I can't since there is no ascx file... How can I do this properly?
I recently bought domain and hosting from godaddy.com and uploaded my website files based on asp.net on server.
The problem is when i run Default.aspx file in visual studio it runs properly but same set set of files when ran after uploading on server gives error in web.config file.
Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.
Details: To enable the details of this specific error message to be viewable on remote machines, please create a <customErrors> tag within a "web.config" configuration file located in the root directory of the current web application. This <customErrors> tag should then have its "mode" attribute set to "Off".
<?xml version="1.0"?> <!-- Note: As an alternative to hand editing this file you can use the web admin tool to configure settings for your application. Use the Website->Asp.Net Configuration option in Visual Studio. A full list of settings and comments can be found in machine.config.comments usually located in WindowsMicrosoft.NetFrameworkv2.xConfig -->
I have created an ASP page to display records for auditor review and response. The page consists of two repeaters that display 5 rows from a database at a time. for each row displayed, a RadioButtonList, containing two buttons is attached. If the second button is selected, an input text box is displayed to allow auditor comments.
My situation is that I cannot find a way to identify which row is being selected? When I select the Button that should enable the text box, I'm receiving the following error:
"Object reference not set to an instance of an object"
I'm just starting out in ASP coding and would like to know what I'm not doing right?
