example23.cs

public class MembershipService : IMembershipService
    {
        private readonly MembershipProvider _provider;
 
        public MembershipService()
            : this(null)
        {
        }
 
        public MembershipService(MembershipProvider provider)
        {
            _provider = provider ?? Membership.Provider;
        }
 
        public int MinPasswordLength
        {
            get
            {
                return _provider.MinRequiredPasswordLength;
            }
        }
 
        public bool ValidateUser(string userName, string password)
        {
            if (String.IsNullOrEmpty(userName)) throw new ArgumentException("Value cannot be null or empty.", "userName");
            if (String.IsNullOrEmpty(password)) throw new ArgumentException("Value cannot be null or empty.", "password");
 
            return _provider.ValidateUser(userName, password);
        }
 
        public MembershipCreateStatus CreateUser(string userName, string password, string email)
        {
            if (String.IsNullOrEmpty(userName)) throw new ArgumentException("Value cannot be null or empty.", "userName");
            if (String.IsNullOrEmpty(password)) throw new ArgumentException("Value cannot be null or empty.", "password");
            if (String.IsNullOrEmpty(email)) throw new ArgumentException("Value cannot be null or empty.", "email");
 
            MembershipCreateStatus status;
            _provider.CreateUser(userName, password, email, null, null, true, null, out status);
            return status;
        }
 
        public bool ChangePassword(string userName, string oldPassword, string newPassword)
        {
            if (String.IsNullOrEmpty(userName)) throw new ArgumentException("Value cannot be null or empty.", "userName");
            if (String.IsNullOrEmpty(oldPassword)) throw new ArgumentException("Value cannot be null or empty.", "oldPassword");
            if (String.IsNullOrEmpty(newPassword)) throw new ArgumentException("Value cannot be null or empty.", "newPassword");
 
            // The underlying ChangePassword() will throw an exception rather
            // than return false in certain failure scenarios.
            try
            {
                MembershipUser currentUser = _provider.GetUser(userName, true /* userIsOnline */);
                return currentUser.ChangePassword(oldPassword, newPassword);
            }
            catch (ArgumentException)
            {
                return false;
            }
            catch (MembershipPasswordException)
            {
                return false;
            }
        }
    }