.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
david stephan
Gaurav Pal
Post New Web Links

Error "Object reference not set" when I try to set a Navigation Property

Posted By:      Posted Date: August 30, 2010    Points: 0   Category :ASP.Net
I'm using Entity Framework. The following code throws a runtime error "System.NullReferenceException: Object reference not set to an instance of an object." The line before the error, it looks like newControl is in fact instantiated.My model has a Control entity and a ControlType entity. Control includes the Navigation Property "ControlType." I'm trying to set ControlType.Type = 2.SurveyFormControlsModel.Control newControl = new SurveyFormControlsModel.Control(); newControl = CreateControl(childTokenName, ControlTypeEnum.TextBox); newControl.ControlType.Type = 2; // <<--ERROR HERE context.Controls.AddObject(newControl);                                SurveyFormControlsModel.Control newControl = new SurveyFormControlsModel.Control();                                 if (listItems.Count == 0)                                 {                                     newControl = CreateControl(childTokenName, ControlTypeEnum.TextBox);                    &

View Complete Post

More Related Resource Links

Jscript error: Object does not support property or method


 Hi, i have little knowledge on javascript but i need to use this code get from somewhere for a jquery to work.

I face this "Jscript runtime error: Object does not support property or method" whenever im trying to run this page.

In my experience, im get this error msg 9 out of 10 times i use javascript in my system.

Im using Microsoft Visual web developer 2008, i wonder if this is related to my problem, i not sure there is anything i need to add as reference or update anything.

But anyway, in short, i just couldn't use javascript code when using this development tool because of this sort of error.

Anyway, it happen that last time i tried use the same type of jquery code in another project and it seems to work well without an error.

But now when im try to use it again in this recent project i created, it come out with this error and i have no idea how to solve it even look through google and this forum.

It doesn't really seems like its the code problem itself although im not sure, because any javascript code just couldn't work.

So below is my code that i need to use.

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" ></script>
<script type="text/javascript" src=&quo

Registering controls of current assembly object reference NOT set error


Hi There,

I have created a simple ASP.net Web Application (2.0) and have added a web user control.

Now in my page I have added this control but I have registered like this,

<%@ Register Assembly="WebApplication1" Namespace="WebApplication1" TagPrefix="Custom" %>

Which means I want to access all the controls in my current Web Application project

Then I have added my user control like this,

<Custom:MyUserControl ID="MyUserControl1" runat="server" PublicProperty="Hello" />

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. Any ideas?


Using Dynamic Property inside Html Helper with Razor fires an error



I have the following with Razor:

@Html.GoogleAjax(View.GoogleAjaxKey, new String[,] { { "jquery", "1.4.2" } })

And the I get a strange error:

  'System.Web.Mvc.HtmlHelper<object>' has no applicable method named 'GoogleAjax' but appears to have an extension method by that name. Extension methods cannot be dynamically dispatched. Consider casting the dynamic arguments or calling the extension method without the extension method syntax.

What is strange is that it works fine using:

@Html.GoogleAjax("123", new String[,] { { "jquery", "1.4.2" } })

I tried the following code line:


And the key is displayed just fine so the problem is how I use the value of @View.GoogleAjaxKey into Html.GoogleAjax.

Do I need to change something on my Html Helper? Here it is:

    public static MvcHtmlString GoogleAjax(this HtmlHelper helper, String key, String[,] libraries) {


error in MicrosoftAjax.js: Cannot read property '_notified' of null


I am cross testing my project with multiple browsers: IE7, Firefox and Chrome.

One one page I have a dynamically built table with two DropDownLists and CascadingDropDown extenders. Maybe the only thing special about the drop down lists is, that I add a "onChange" for the second drop down list in each row which shows or hides the list depending on the value populated from the web services.

All of this works perfectly in IE7 and Firefox, but Chrome does not execute the JavaScript in the onChange attribute and the error console says:

Uncaught TypeError: Cannot read property '_notified' of null

Object or Property is not supported in IE8 - javascript error



I am using following code line in my web app through external javascript file.






both these methods are working fine in IE6 but failing in IE8 with a error: "Object or Property is not supported".


any solution would be appreciated!



Viewmodel property not set to [Required] yet getting error message saying it is?


I have a viewmodel that i use for my view

public int SelectionId{ get; set; }        
public IEnumerable<Selections> Selections { get; set; }

Notice that SelectionId is not decorated with [Required]. In my view, i use DropDownFor like this:

<%= Html.DropDownListFor(m => m.SelectionId, new SelectList(Model.Selections, "Id", "Name"), "--- Select ---")%>

It should be possible to not select anything from the dropdown, resulting in model.SelectionId = 0, which is fine. Why do i get a "SelectionId field is required" error when i Post?  If i do this:

<%= Html.DropDownList(mySelectionId, new SelectList(Model.Selections, "Id", "Name"), "--- Select ---")%>

I no longer get the error if i dont select anything, which is what i want - but no way to bind it to the id if the user does select something

thanks for any help!

error in MVC2 on empty string form fields which are required: "This property cannot be set to a null

In model I have:[DisplayName("ISBN")] [Required(ErrorMessage = "ISBN is required.")] [StringLength(50, ErrorMessage = "ISBN book must have max {1} chars.")] [DisplayFormat(ConvertEmptyStringToNull = false)] public string isbn { get; set; }But when I submit form with empty field ISBN I have an error - ConstraintException: This property cannot be set to a null value.I have find that other people have the same problem and they say that debbugger in VS2010 works wrong - yes ?http://p2p.wrox.com/book-professional-asp-net-mvc-2/79788-constraintexception-unhandled-user-code.html#post259245http://efreedom.com/Question/1-3129080/Server-Side-Validation-REQUIRED-String-Property-MVC2-Entity-Framework-Workhttp://mvcmusicstore.codeplex.com/workitem/6604

Object reference not set to an instance of an object error.

i've installed the VSeWSS.msi on VS 2005, i'm using SPS 2007, i'm developing on my workstation in C#, i've added the Mircosoft.Sharepointserver dll reference to my project but i still can't deploy a very basic webpart. i get the "Object reference not set to an instance of an object" error but there's no reference to a line, column, project or anyhting. very frustrating. any suggestions/links whould be appreciated.

SQL Server 2008 Express Setup failure: Unknown Property Error

I am trying to install SQL server 2008 on windows 7 but it returns the following error when almost done with installation: TITLE: SQL Server Setup failure. ------------------------------ SQL Server Setup has encountered the following error: Unknown property. . ------------------------------ BUTTONS: OK ------------------------------   Can someone please assist me with this, I have tried for more than a week to go around it. I have also searched online for solutions but in vain. Looking into the log files, I see these: 2010-09-05 21:04:41 Slp: Running Action: Install_SqlBrowser_Cpu32_Action 2010-09-05 21:04:41 Slp: Target package: "C:\Softwares\Database and Management\SQLEXPRADV_x86_ENU\x86\setup\sqlbrowser.msi" 2010-09-05 21:04:46 Slp: InstallPackage: MsiInstallProduct returned the result code 0. 2010-09-05 21:04:46 Slp: RunMsiCore succeeded. 2010-09-05 21:04:46 Slp: Checkpoint: INSTALL_SQLBROWSER_CPU32_ACTION 2010-09-05 21:04:46 Slp: Completed Action: Install_SqlBrowser_Cpu32_Action, returned True 2010-09-05 21:04:46 Slp: ---------------------------------------------------------------------- 2010-09-05 21:04:46 Slp: Running Action: Install_SqlSqmShared_Cpu32_Action 2010-09-05 21:04:47 Slp: Error: Action "Install_SqlSqmShared_Cpu32_Action" threw an exception during execution. 2010-09-05 21:04:47 Slp: Microsoft.SqlServer.Setup.Chainer.Workflow.ActionExec

How to change the value of a foreign key field/navigation property?

How can I change the value of a foreign key field?  E.g. in the Product list view instead of the value of the field Supplier.CompanyName I want to display the Supplier.Region. I searched my whole code to get a clue, googled for "change navigation property" and looked in the docs but unfortunately I did not find any hint. If you know where to find the answer, please let me know too the source of your knowledge!          

Login error - Object reference not set to an instance of an object.

Hi all,I've set up the login section as a user control. WheneverI log in I get a "Object reference not set to an instance of an object", with the code stopping on this line: if (Membership.ValidateUser(txtUserName.Text,txtPassword.Text))Can anyone tell me how to fix this please?protected void LoginButton_Click(object sender, EventArgs e) { TextBox txtUserName = loggedin.FindControl("UserName") as TextBox; TextBox txtPassword = loggedin.FindControl("Password") as TextBox; CheckBox ckbRememberMe = loggedin.FindControl("RememberMe") as CheckBox; if (Membership.ValidateUser(txtUserName.Text,txtPassword.Text)) { FormsAuthentication.RedirectFromLoginPage(txtUserName.Text, ckbRememberMe.Checked); } else { // Msg.Text = "Login failed. Please check your user name and password and try again."; } } <asp:LoginView ID="loggedin" runat="server"> <AnonymousTemplate> <asp:Login ID="Login1" runat="server"> <LayoutTemplate> <table id="mainbox" width="400"> <tr> <td width="150" class="label">

Validation error: This property can not be set to a null value [updated with test case!]

Hi, In a dynamic data web application, I get a validation error on a non-null nvarchar(50) column in ListDetails.aspx, even though I have entered a value which should be accepted. The validation error is: "This property cannot be set to a null value.". I can not reproduce this on northwind/adventureworks. Any ideas? UPDATE: I have created a complete test case: http://printf.no/DynamicDataBugTest.zip (The archive was scanned with the latest AVG definitions before uploading to my private secure dedicated FreeBSD server) The test case contains: One Dynamic Data Web App project One MS SQL Server 2005 database backup which contains a single table with three columns One screenshot showing how the error manifests itself I am fairly convinced now that this is a reproducible DD bug. -Andreas

Strange Repeater Error, Object reference not set, Label not visible etc etc..

Hi Everyone,This is very strange and as of yet I cant seem to get round it, although it is a somewhat easy error to identify it is however becoming very annoying as everything I try doesn't seem to work...The repeater displays results for upcoming subscribers birthdays and after their day and month ("dd/mm/") I have a label to display the current year. This causes the old error of: 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 55: Label lblYear = e.Item.FindControl("lblYear") as Label;Line 56: Line 57: lblYear.Text = DateTime.Now.Year.ToString();Line 58: }Line 59: As you can see the object is set correctly - The ASPX is below, for saving time on reading etc I've posted the repeater script only and not the whole page, although I can do if needs be.I've tried a number of things with subtle differences but to no avail: with Literal, same error - Tried inserting the year directly via <%#((system.datetime).now.year.tostring())%> or something to that effect, this also doesnt

Error while export to pdf-Object reference not set to an instance of an object

Hello, I am getting error while rendering the report to pdf in SSRS 2008. This is happening randomly and sometimes I get this error. I have SQL Server 2008 SP1 installed in my system . I installed the cumulative update 1 for SP1 also but no luck. Every time when export to pdf fails, SSRS is creating the dump file in the logs. I have captured the log of this specific error. Please let me know if you have any idea about this.   reportrendering!ReportServer_0-297!1ec4!03/30/2010-10:32:57:: e ERROR: Throwing Microsoft.ReportingServices.ReportProcessing.UnhandledReportRenderingException: An error occurred during rendering of the report., ; Info: Microsoft.ReportingServices.ReportProcessing.UnhandledReportRenderingException: An error occurred during rendering of the report. ---> Microsoft.ReportingServices.OnDemandReportRendering.ReportRenderingException: An error occurred during rendering of the report. ---> System.NullReferenceException: Object reference not set to an instance of an object.   at Microsoft.ReportingServices.Rendering.HPBProcessing.Paragraph.get_SpaceBefore()   at Microsoft.ReportingServices.Rendering.RichText.LineBreaker.FlowParagraph(Paragraph paragraph, Directions direction, IntPtr hdc, Single dpiX, FontCache fontCache, FlowContext flowContext, Boolean keepLines, SizeF flowContextSize, Int32& contentOffset)   at Mi

Error Creating Control - 'asp:UpdatePanelAnimationExtender' could not be set on property 'Animati

It doesn't seem to matter what I try to make the animation do, I keep getting this shown in the designer. No one else on google seems to be getting that problem either. Note: it doesn't cause debugging or runtime issues... in fact, the only negative thing it does is make it extremely annoying when I look at the designer... I'm going to have about 12 of these updatepanelanimations firing everytime the timer ticks too :(. MasterPage file has the toolkitscriptmanager on it. Here is my designer code for the page I'm having the issue on:<%@ Page Title="" Language="vb" AutoEventWireup="false" MasterPageFile="~/MasterPage.Master" CodeBehind="TimeLine.aspx.vb" Inherits="TimeLine.WebForm1" %> <%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %> <asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server"> <asp:Timer ID="Timer1" runat="server" Interval="7000"> </asp:Timer> <asp:Panel ID="Panel1" runat="server" Height="285px" HorizontalAlign="Center" Width="970px" BackImageUrl="~/Images/Img.jpg"> <br />

Help with Object reference not set to an instance of an object. error.

I was given a chunk of code to help with accessing dynamic forum controls about a week back and when I implemented the code I get the error "Object reference not set to an instance of an object". I asked in the thread the code was given but have not recived an answer yet (asked about 4 days ago) and I think that is beause  the thread is marked as resolved. The line of code  causing the error is   if(t.Equals(this.ddlAmountToAdd.ClientID)&&!string.IsNullOrEmpty(v))    And here is the full code for the c# .Net 4 page.using System; using System.Collections.Generic; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; public partial class GameInformation_AddUpcomingRelease : System.Web.UI.Page { public string[] Regions = { "USA", "Japan", "Europe", "Other" }; //Create a string array of regions. public string[] Platforms = { "PlayStation 3", "X-Box 360", "Wii", "Computer", "PSP", "Other" }; //Create a string array of platforms. protected void Page_Load(object sender, EventArgs e) { ddlPlatform1.DataSource = Platforms; ddlPlatform1.DataBind(); ddlRegion1.DataSource = Regions; ddlRegion1.DataBind(); } protected override void OnInit(EventArgs e)

Configure managed accounts - object reference not set to an instance of an object - error

I was working in central admin and activated the managed accounts password change for the farm account with the option to change the password now.  I got the email notification that the password was changed and it seems in the log files that it did update all the credentials that were used with the account.  Problem is now that when I hit the configure managed accounts link in central admin all I get is the error: Error Object reference not set to an instance of an object.  Troubleshoot issues with Microsoft SharePoint Foundation. Correlation ID: c6dc7a46-894f-4b85-8711-8af1e8ec7903 Date and Time: 8/23/2010 9:20:20 AM Added information from logs: 08/23/2010 10:41:33.24  w3wp.exe (0x0F2C)                        0x07FC SharePoint Foundation          Logging Correlation Data       xmnv Medium   Name=Request (GET:http://cmtcalcium:33333/_admin/ManagedAccounts.aspx) b9fae5a9-7405-407d-87fc-239dc0ff59d0 08/23/2010 10:41:33.24  w3wp.exe (0x0F2C)                        0x07FC SharePoint Foundation     &n
ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend