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

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

Simple error connection string null reference

Posted By:      Posted Date: September 16, 2010    Points: 0   Category :ASP.Net
 It is failing on SqlHelper.ExecuteNonQuery(System.Configuration.ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString     public static string GetAboutMeName(string sUserID, string connectionString)        {             SqlParameter[] parameters = new SqlParameter[2];                      parameters[0] = new SqlParameter("@sUserID", SqlDbType.VarChar, 50);            parameters[0].Value = sUserID;             parameters[1] = new SqlParameter("@sResult", SqlDbType.NVarChar, 1000);            parameters[1].Direction = ParameterDirection.Output;             // Execute the stored procedure            SqlHelper.ExecuteNonQuery(System.Configuration.ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString, CommandType.StoredProcedure, "sprGetAboutMeName", parameters);         &n

View Complete Post

More Related Resource Links

Web config connection string error: a field initializer can not reference the nonstatic field



I am try to get connection string from web config, but I got error" a field initializer can not reference the nonstatic field, method, or property '_default.connStr'. I search a lot. It says that I need constructor, but I am not sure how to write the constructor at class: public partial class _Default : System.Web.UI.Page

Here is my code:

{public partial class _Default : System.Web.UI.Page

    string txt;
    string username;
    OleDbCommand myCommand = null;
    OleDbDataReader myDataReader = null;

//retrieve the connection string from the ConnectionString Key in Web.Config
    string connStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

    //create a new OleDB connection
    OleDbConnection myConnection = new OleDbConnection(connStr);

protected void Page_Load(object sender, EventArgs e)

            string strOledb = @"select * from tableone";
            OleDbCommand myCommand = new OleDbCommand(strOledb);

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

Null reference message Custom Error page

how come a Null session value that is called, doesn't get directed to the Custom Error Page?

The Connection String Reference

Excellent site which provides readymade connection strings for all major data sources.

Safe Connection String error when installing new


I am trying to install a new SharePoint2010 WSF on a Virtual Server.

Team Foundation Server already runs fine.

I run the Install and everytime I either point to a databasde or let SharePoint create it's own I get the following error.

Here my flickr picture of the message box.


It's safe.

Its a missing method exception  ( System.String.Microsoft.SharePoint.Administration.SPSqlConntionString.GetWYukonSafeConnectionString(String)

Did I download the wrong setup file?

We have a 2003 WSS SharePoint and I'm trying to take thier old database and attach it and upgrade them to 2010 on a test Virtual first.

Any pointers, links, or advice is appreciated.




SQL Connection String

We can learn or know how can we connect the database from our .net. This will help for freshers or .NET beginners!

abstract away the source of the connection string using a class with a static property.

ASP.NET provides a configuration system we can use to keep our applications flexible at runtime. In this article we will examine some tips and best practices for using the configuration system for the best results.

The element of a web.config file is a place to store connection strings, server names, file paths, and other miscellaneous settings needed by an application to perform work. The items inside appSettings are items that need to be configurable depending upon the environment, for instance, any database connection strings will change as you move your application from a testing and staging server into production.

Let's abstract away the source of the connection string using a class with a static property.

connection string question from a newbie


when publishing  in the webmatrix dialogue it asks for "destination connection string" for my "database.mdf"

I was not sure what it was so I pasted this from my web.config file :

Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\database.mdf;Integrated Security=True;User Instance=True

it all published ok, but wont run, so I guess it has somthing to do with this connection string or some kind of configuration issue.

My question is this, What should go in the field for "Destination connection string"

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?


Intermittant error: "A connection attempt failed because the connected party did not properly respon



I'm having a doozy of a problem, and can't find a solution.  I have a WFC Web Service installed to a pair of servers, and accessed through a load balancer.  I am accessing the service from an ASP.NET client app, also via WCF.  The Client is not load balanced.

I'm getting an intermittant error:

(Inner Most Exception) System.Net.Sockets.SocketException:  A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond x.x.x.x:80

(Middle Exception) System.Net.WebException: Unable to connect to the remote server

(Outer Exception) System.ServiceModel.EndpointNotFoundException:  Could not connect to http://<MYSite>/<MYApp>/<MYService>.svc. TCP error code 10060: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond x.x.x.x:80.

I can reproduce this error with about 20% reliability if I execute the exact same page request on the client from 2 browsers at the same time.  When the problem occurs, the successful p

Modifying connection String in Web config using Install Wizard



Im trying to create a Web Deployment Project, the built in setup and deployment is very good in Visual Studio, i need to able to add an additional step in the setup to change the connection string in the Web config file. Ive seen a lot of articles on how to do this and in particular this http://weblogs.asp.net/scottgu/archive/2007/06/15/tip-trick-creating-packaged-asp-net-setup-programs-with-vs-2005.aspx#7162670 I am however stuck on the final part of this tutorial, im using the code Scott provided but have two errors,  heres part of my code where the errors are

using System;
using System.Configuration;
using System.Configuration.Install;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.DirectoryServices;

 void ConfigureDatabase(string targetSite, string targetVDir, string connectionString)
            // Retrieve "Friendly Site Name" from IIS for TargetSite
            DirectoryEntry entry = new DirectoryEntry("IIS://LocalHost/" + targetSit

Page.FindControl Causing Null Reference Exception


Hi guys,

I developed a page in VWD 2008 and it works perfectly locally, but when I deployed it on the server every Page.FindControl() call is causing the NullReference Exception "Object reference not set to an instance of an object. " Can anyone help me out? Code is below


Mike Marshall

            For i As Integer = 1 To 10
                If (CType(Page.FindControl("last_" & i), TextBox).Text.Length > 0) Or (CType(Page.FindControl("first_" & i), TextBox).Text.Length > 0) Or (CType(Page.FindControl("dob_" & i), TextBox).Text.Length > 0) Then
                    Dim person_entry(7) As String
                    person_entry(0) = info_list.Count - 1
                    person_entry(1) = CType(Page.FindControl("last_" & i), TextBox).Text
                    person_entry(2) = CType(Page.FindControl("first_" & i), TextBox).Text
                    person_entry(3) = CType(Page.FindControl("dob_" & i), TextBox).Text
                    person_entry(4) = CType(Page.FindControl("appear_" & i), TextBox).Text
                    person_entry(5) = CType(Page.FindControl("mental_" & i), TextBox).Text
                    person_entry(6) = CType(Page.FindControl("behave_" & i), TextB

linq and max, if return null return error


hi there
i have this query :

var result2 = (from TH in DB.Threshold
                          where TH.ProductSKUID == int.Parse(HID_ProductSKUID.Value)
                          select TH.ThresholdID).Max();

the problem is that if this query does not find any items, return null, so thow exception
how can i do to return 0??

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

The underlying connection was closed: An unexpected error occurred on a send.


I am consuming a third party web service wsdl using my .net aps.net page. And I am getting following error message. Cannt get to resolve it. Its working on my machine but not in my development machine. I have installed the certificate also in certificates on that machine. Can somone please help.?

Error -->  The underlying connection was closed: An unexpected error occurred on a send.





Custom tool error: Failed to generate code for the service reference 'CompanyService'. Please che


A little background because I feel I have an out of the ordinary architecture in place and don't know if this is contributing to the problem. 

We have an existing ASP.net application that is undergoing expansion.  The new functionality is all written in Silverlight 4.  As part of that expansion I gutted all the old Linq to SQL and put Entity Framework 4 into place.  To do this I created a standard .net Class Library and added my edmx files there.  Naturally, the business entities created by this cannot be used in Silverlight.  So I created a Silverlight Class Library and added all the business entities to that Silverlight Class Library as linked files.  I changed the name space to be the same.

So I have the following assembly / namespaces

Company.Project.Dal.csproj / Company.Project.Entities (.net 4 class library)

Company.Project.Entities.csproj / Company.Project.Entities (SL4 class library)

With this architecture I was able to share my business entities with my SL enabled web services, my asp.net projects, my silverlight projects.  Really it's a beautiful thing.

Once this was done I added "message" classes to Company.Project.Dal and again shared them with the other entites using linked files.  These messages are things like MyObjectRequest; they are class

FileUpload error: Object reference error


I have a FormView with a FileUpload to upload an image in a database.

I keep getting an object reference error.(view code)

I am using this same script to upload the image to the database, but when I try to update the file upload I get the error.    

string strFilePath=Server.MapPath("\\images\\"+fupdImage.FileName);

        Byte[] image=null;
        HttpPostedFile imgVid=FileUpload.PostedFile;

        image=new Byte[imgVid.ContentLength];//Object reference not set to an instance of an object.

        if(FileUpload.HasFile) {
        string imageFile=FileUpload.PostedFile.FileName;
        int index=imageFile.LastIndexOf(".");
        string fileFormat=imageFile.Substring(index+1);


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