Question

I have the following code

private string conn(string name)
    {
        return ConfigurationManager.ConnectionStrings[String.Format("{0}ConnectionString", name)].ConnectionString;
    }

But I keep getting the error below on the return statement.

System.NullReferenceException: Object reference not set to an instance of an object

Can you please tell me what is wrong with this?

Answer 1

Your code looks for connection string named name + “ConnectionString”.
It look’s your web.config does not have connection string with this name.
Add connection string with generated name or change the code like this:

    private string conn(string name)
    {
        var coll = ConfigurationManager.ConnectionStrings[String.Format("{0}ConnectionString", name)];
        if (coll != null)
        {
            return coll.ConnectionString;
        }
        else
        {
            return null;
        }
    }