ConfigurationManager.AppSettings returning null

Question

I am using ConfigurationManager.AppSettings["smtpHost"] to read a value from the app.config file in my business logic layer, but the value returned is always null, even though the key exists and it has a value, Does any one know why?

App.config file in BLL:

<appSettings>
  <add key="smtpHost" value="smtp.gmail.com" />
</appSettings>

I added the same thing to the web.config file.

And I try to get;

var host = ConfigurationManager.AppSettings["smtpHost"];

Answer 1

Your code is correct (i have tested), you need to make sure that your app.config file is in your main project (exe).