Static Objects | Custom ConfigurationManager for Environment Independent Web.config

I am working on a typical .net web app which is first deployed at test environment - ENV- T and then after complete testing it is moved to Production ENV - P. Our hosting provider will not deploy anything directly on Prod instead it is first deployed on Test and then they sync it to PROD.

Also these two environment Env-T and Env-P are totally different. So the Web.Config settings are different too.

So to deploy anything on ENV-P we have to change the web.config of ENV-T as per Env-P. And then ask the hosting vendor to sync the application and then we have to revert.

To solve this issue i thought of making the Web.config environment independent. So i wrote a custom ConfiguraitonManager class which will identify the current environment in which the application is working in and will load values accordingly.

High level Approach : We will have two Web.config one in ENV-T folder and another in ENV-P folder. Depending upon the machine name we will identify the environment. If it is ENV-T load the Web.Config values from ENV-T folder and if it is ENV-P load the values from ENV-P folder.

Here is the my class :

public static class ConfigurationManager
{
    static Configuration _config;
    static NameValueCollection nameValueColl;
    public static NameValueCollection AppSettings
    {
        get
        {

if (nameValueColl == null)
            {
                if (_config == null)
                    _config = LoadConfig();
                nameValueColl = new NameValueCollection();
                foreach (KeyValueConfigurationElement configElement in _config.AppSettings.Settings)
                {
                    nameValueColl.Add(configElement.Key, configElement.Value);

                }

            }
            return nameValueColl;
        }
    }

    private static Configuration LoadConfig()
    {
        string basePath = string.Empty;


        if (System.Web.Hosting.HostingEnvironment.ApplicationVirtualPath != null)
        {
            basePath = System.Web.Hosting.HostingEnvironment.ApplicationVirtualPath;
        }

        string machineName = System.Environment.MachineName;

        if (machineName.Equals("MachineA"))
        {
            _config = WebConfigurationManager.OpenWebConfiguration(basePath + "Test");
        }
        else if (machineName.ToLower().Equals("MachineB"))
        {
            _config = WebConfigurationManager.OpenWebConfiguration(basePath + "Prod");
        }


        return _config;
    }

}

Now all i have to do is write

ConfigurationManager.AppSettings["KEY1"]

to read the Appsetting key "KEY1" and i get the correct value for that particular environment.

Question : I have a key 开发者_StackOverflow <add key="NoOfRecords" value="50"/> .

For some reason after several hits ( in a day or two) the value i get for NoOfRecords key is 50,50,50,50,50 instead of 50. Possible reason : If i add a key,value say "NoOfRecords","50" to a NameValueCollection object which Already has "NoOfRecords","50" it will store the value as "NoOfRecords","50,50".

But again how this is possible cause just before this code block i am creating a new object and also i have a null check for this nameValueColl variable.