How to Verify if the user belongs to an Active Directory user Group in C#.NET

I am writing code to verify whether user belongs to a particular AD group or not.

When i checked this is how the group details are:

"CN=Building - 28 (ALL),OU=Exchange Auto Groups,OU=AM,OU=schwab,DC=am,DC=corp,DC=schwab,DC=com"

This is the group that I want to verify if a user (Ex: user1) belongs to this group or not.

I am try开发者_如何转开发ing to play with the method that returns the list of Groups that the User belongs to. Here I have to filter based on the Group.

Code to bring the active directory user groups that the user belongs to:

private List<string> GetUserGroupMembership(string userName)
    {

        var directoryEntry = new DirectoryEntry();
        DirectorySearcher search = new DirectorySearcher();
     **//filter based on the username**
        search.Filter = String.Format("(cn={0})", userName);
     **//How to filter based on the Group "CN=Building - 28 (ALL),OU=Exchange Auto Groups,OU=AM,OU=schwab,DC=am,DC=corp,DC=schwab,DC=com"**
        search.PropertiesToLoad.Add("memberOf");

        List<string> groupsList = new List<string>();

        SearchResult result = search.FindOne();
        if (result != null)
        {
            int groupCount = result.Properties["memberOf"].Count;

            for (int counter = 0; counter < groupCount; counter++)
            {
                groupsList.Add((string)result.Properties["memberOf"][counter]);
            }
        }
        return groupsList.ToList();
    }

I appreciate your response.

Thanks

If you are using .NET 3.5 or later then have a look at System.DirectoryServices.AccountManagement. These classes are far easy to work with. For example,

PrincipalContext pc = new PrincipalContext(ContextType.Domain);
UserPrincipal user = UserPrincipal.FindByIdentity(pc, "johndoe");
var groups = user.GetAuthorizationGroups()  // or user.GetUserGroups() 

Have a look at these article that gives a bit of overview for the same:

http://anyrest.wordpress.com/2010/06/28/active-directory-c/

http://msdn.microsoft.com/en-us/magazine/cc135979.aspx#S5