Switch to SQL membership provider from AD membership provider runtime - asp.net

Question

In my asp.net application admin functionality, I am trying to combine AD authentication and form authorization for creating the users, roles and Assign users to roles etc. I have configured MembershipADProvider and AspNetSqlMembershipProvider in my web.config with MembershipADProvider as the default one. After user logs in using AD authentication, I need to switch/assign my membership object to use AspNetSqlMembershipProvider in order to get all the users from membership object (from dbo.aspnet_Users table). How do I switch the provider during run time? I have tried different approaches after searching for this issue and none of that seem to work for me so far.
Here are couple of approaches I tried:
1. foreach (MembershipProvider mp in Membership.Providers)
{
if (mp.Name == "MembershipADProvider")
{
Membership.Providers.Remove(MembershipADProvider");
MembershipUserCollection users = Membership.GetAllUsers();
ddlUsers.DataSource = users;
ddlUsers.DataBind();
break;
}
}
Membership.Providers.Remove(MembershipADProvider"); - doesn't work as it's not supported..
Also, tried to clear the Membership.Providers and then add only the type of AspNetSqlMembershipProvider which are also not supported.
I can't set Membership.Provider with value from
Membership.Providers["AspNetSqlMembershipProvider"] as Membership.Provider is a read only property.
I tried to swtich the connection string between 2 providers, which didn't swtich the provider, as both are different types of providers..if both were sqlserver providers this would have worked I believe.
Please let me know if anybody has successfully implemented or if at all this is a plausible approach. Thank You!

Answer 1

You would pass an explicit provider to your code, rather than taking a dependency on Memebership directly (which just wraps the one flagged as default in the config). There is no need to swap them in and out at runtime, think how this would affect thread safety.
So rather than saying Membership.GetAllUsers(); you would do something like (I don't have a compiler to hand):
public UserSerivce : IUserService
{
private MembershipProvider provider;
public UserService(MembershipProvider provider)
{
this.provider = provider;
}
public IEnumerable<MembershipUser> GetUsers()
{
return provider.GetAllUsers();
}
public void DoSomethingElseUseful()
{
...
}
}
And then to use it for a particular provider:
var service = new UserService(Membership.Providers["mySqlMembershipProvider"]);
var users = service.GetUsers();
Or if using AD specific code:
var service = new UserService(Membership.Providers["myADMembershipProvider"]);
var users = service.GetUsers();
Using DI in this way also helps keep code testable.

Answer 2

If all you need a list of users in the aspnet_Users table, just connect to your database with System.Data.SqlClient objects and query the table. There is no reason (that you mentioned) you need to use a membership provider to get that data.
Having said that, your membership/authentication scheme sounds like it may have some design issues, perhaps best tackled in a different question, but I think it might be useful to you if you sought comment on what you are trying to accomplish overall with the multiple membership providers.
Edit: I found some potentially useful posts on using multiple membership providers. It looks like the general idea is to implement custom code handling the Login.Authenticate event on your Login control, and use Membership.Providers["ProviderName"].ValidateUser to attempt authentication with each provider.
http://www.stevideter.com/2008/03/20/using-two-membership-providers-for-aspnet-logins/
http://forums.asp.net/p/1112089/1714276.aspx