Add Sitecore AD Membership Provider at runtime

Before you refer this blog, refer this blogpost
https://santoshpoojari.blogspot.com.au/2017/03/sitecore-active-directorysitecoreadmemb.html

I have taken more generic approach to add this. I have refined the above method with c# generic constraint.

Things to be taken care.      

We cannot use below Providers add due: Exception Details: System.NotSupportedException: Collection is read-only.

//Membership.Providers.Add(provider);
Therefore we should use utility class that give extension method AddTo.

http://stackoverflow.com/questions/1432508/programmatically-adding-a-membership-provider

Generic Membership Provider

  
 public static void InitialiseProviders <T>(T provider, string providerName, NameValueCollection providerConfiguration) where T : MembershipProvider
        {
            provider.Initialize(providerName, providerConfiguration);
            provider.AddTo(Membership.Providers);
            //We cannot use below Providers add due: Exception Details: System.NotSupportedException: Collection is read-only.
            //Membership.Providers.Add(provider);
        }

Utility Extension Method

public static class ProviderUtil
{
    static private FieldInfo providerCollectionReadOnlyField;

    static ProviderUtil()
    {
        Type t = typeof(ProviderCollection);
        providerCollectionReadOnlyField = t.GetField("_ReadOnly", BindingFlags.Instance | BindingFlags.NonPublic);
    }

    static public void AddTo(this ProviderBase provider, ProviderCollection pc)
    {
        bool prevValue = (bool)providerCollectionReadOnlyField.GetValue(pc);
        if (prevValue)
            providerCollectionReadOnlyField.SetValue(pc, false);

        pc.Add(provider);

        if (prevValue)
            providerCollectionReadOnlyField.SetValue(pc, true);
    }
}

Initialize the LDap AD Configuration and call the generic method

 public static NameValueCollection LdapSitecoreProviderConfiguration
        {
            get {

                 NameValueCollection config = new NameValueCollection();                                 
                 config["type"] = "LightLDAP.SitecoreADMembershipProvider";
                 config["name"] = "SomeProviderName";

                 config["connectionStringName"] = "LDAPConnString";
                 config["applicationName"] = "sitecore";
 
                 config["connectionUsername"] = ConfigurationManager.AppSettings["AppSettingKeys-UserName"];
                 config["connectionPassword"] = ConfigurationManager.AppSettings["AppSettingKeys-Password"];
 
                 config["minRequiredPasswordLength"] = "1";
                 config["minRequiredNonalphanumericCharacters"] = "0";
                 config["requiresQuestionAndAnswer"] = "false";
 
                 config["requiresUniqueEmail"] = "false";
                 config["connectionProtection"] = "secure";
 
                 config["attributeMapUsername"] = "sAMAccountName";
                 config["enableSearchMethods"] = "true";
 
                 config["customFilter"] = "(memberOf=Your org custom filter)";
                 return config;
            }
        }

InitialiseProviders(new SitecoreADMembershipProvider(), "someldapName", xyz.LdapSitecoreProviderConfiguration);