Receiving error Object reference not set to an instance of an object?

Question

0.00/5 (No votes)

See more:

Hi
I have defined a class "Seller" in this I am using a public string variable as

C#

public string _connectionString = ConfigurationManager.ConnectionStrings["seller"].ConnectionString.ToString();

The above connection string is defined in App.config file used in class library Seller.

When I am calling class Seller

C#

Seller _seller = new Seller();

It throws error

" Object reference not set to an instance of an object" when the cursor reads the above string object??

Its very irritating Error. I tried every thing but didn,t found any solution.
Please help on this.

Thanks

Posted 14-Aug-15 22:57pm

mayank.bhuvnesh

Updated 14-Aug-15 23:16pm

Wendelius

v3

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2015-08-14T23:09:00

Solution 1

So start with the debugger and look at exactly what is going on.
Initially, change that line to just the declaration:

C#

public string _connectionString = null;

and in your Seller class constructor add this:

C#

var o1 = ConfigurationManager.ConnectionStrings["seller"];
var o2 = o1.ConnectionString;
_connectionString = o2.ToString();

Then put a breakpoint on the first line and step through, using the debugger to look at the values - when you know which one is null, you can start looking at why - but until you know that, you are just guessing.

We can't do this for you - we don't have access to your machine or the web.config file.

Posted 14-Aug-15 23:09pm

OriginalGriff

Comments

mayank.bhuvnesh 15-Aug-15 5:53am

I tried the above, now I am receiving error at
var o2 = o1.ConnectionString;

Please find below the App.config File


<configuration>
<connectionstrings>
<add name="seller" connectionstring="server=SQLSERVER; database=seller; uid=sa; password=xxxx" providername="Sysm.Data.SqlClient">
</add></connectionstrings>
</configuration>

OriginalGriff 15-Aug-15 6:11am

So you need to look at why your app.config file is not being read correctly.
Start with the example on MSDN:
https://msdn.microsoft.com/en-us/library/system.configuration.configurationmanager.connectionstrings(v=vs.110).aspx
And see what that gives you.
We can't do any of this for you - we can't access your system!

F-ES Sitecore 15-Aug-15 15:46pm

app.config isn't used on asp.net sites, your connection settings need to be in the web.config file.

mayank.bhuvnesh 16-Aug-15 3:02am

Dear I am using class library project in MVC application and in class library project I am using app.config file only. I even tried the same with web.config file an passing the parameter for connection string to class library but the error is still same.
Now I have hardcoded it but its not the actual solution.