ConfigurationManager.AppSettings getting null?

I did not realize that: 'have a web.config in a separate class library and' was reading the web.config app setting from different web application.

I am using VS2010 target framework 3.5

I don't know what is wrong here but I am getting null when I try to get ConfigurationManager.AppSettings["StoreId"];

private string _storeid = GetStoreId;

public static string GetStoreId
{
    get
    {
        return ConfigurationManager.AppSettings["StoreId"];
    }
}

web.config:

<appSettings>
    <add key="StoreId" value="123" />
</appSettings>

Solution 1:

If you are UNIT TESTING you need A COPY of the APP.CONFIG inside the UNIT TEST PROJECT

Solution 2:

Problem

The usual cause for this is due to context.

Cause

When you have a solution with two projects, if the App/Web.Config is in the main project it wont work if the context of the running application is the second project such as a library, unit test, etc.

Conundrum

To read values from the config in other projects (with System.Configuration) you'll need to move/copy the config file to the project with the running context. Unfortunately duplicating files defeats the tenants of good programming; OOP, Source Code Management, SOLID, etc.

Cool Solution

A nifty solution is adding config file shortcuts in other projects so you only update one file:

It would be nice to divide the contents of config files across project's. Elegantly, like Sharing Assembly Files as per answer #2: https://stackoverflow.com/a/15319582/495455 but alas it's by context

Solution 3:

Disclaimer ;) This post is not to answer OP as it is too late but definitely it would help the readers who end up to this page.

Problem I faced : ConfigurationManager.AppSettings["uName"] returning null in my C# web api project.

Basic Things I checked for :

1) In code ConfigurationManager.AppSettings["uName"] , I was using exact key 'uName' as I had in web.config file,

i.e

<appSettings>
      <add key="uName" value="myValue" />
</appSettings>

Checked that I haven't mis typed as userName instead of uName etc.

2) Since it is a Web API project it would have a file as web.config instead of app.config , and that too in root folder of your project. [refer the image].

Solution :

The solution that worked for me ,

Changed ConfigurationManager.AppSettings["uName"] to WebConfigurationManager.AppSettings["uName"]

and

made sure that I had

<appSettings>
          <add key="uName" value="myValue" />
</appSettings>

in the right file ie.

Right file is not web.config in View folder

neither the debug or release web.config

Solution 4:

and:

<appSettings>
    <add key="StoreId" value="123" />
</appSettings>

is located in the web.config file of your ASP.NET application and not in some app.config file you've added to your class library project in Visual Studio, right? You can't be possibly getting null if this is the case. If you've added this to an app.config of you class library project in Visual Studio then getting null is perfectly normal behavior.

Solution 5:

I just got answer DLL are called from another project not in the project where there are create.so entries in App.config should b move to calling project config file.

For example i have 2 project in my solution one class library and other console application.i have added class library reference in Console application.So if i add app.config file in class library project it through null exception.it works when i added app.config in console application.Hope it works