Reflection for MembershipUser class

aldwinenriquez · March 20th, 2009, 04:52 AM

I would like to modify the readonly property of the MembershipUser class, however I was not able to do it for the IsOnline property since I was not able to get its readonly fieldname.

Iterating through its properties(Instance | Public) and fields(Instance |NonPublic) gives me these:

Properties
0:UserName
1:ProviderUserKey
2:Email
3:PasswordQuestion
4:Comment
5:IsApproved
6:IsLockedOut
7:LastLockoutDate
8:CreationDate
9:LastLoginDate
10:LastActivityDate
11:LastPasswordChangedDate
12:IsOnline
13:ProviderName
Fields
0:_UserName
1:_ProviderUserKey
2:_Email
3:_PasswordQuestion
4:_Comment
5:_IsApproved
6:_IsLockedOut
7:_LastLockoutDate
8:_CreationDate
9:_LastLoginDate
10:_LastActivityDate
11:_LastPasswordChangedDate
12:_ProviderName

How come there isn't a field for the IsOnline property?

Thanks in advance...

philip_cole · March 20th, 2009, 09:44 AM

Not entirely sure what you're trying to achieve, but here's the source code (via Reflector):

Code:

public bool IsOnline
{
    get
    {
        TimeSpan span = new TimeSpan(0, Membership.UserIsOnlineTimeWindow, 0);
        DateTime time = DateTime.UtcNow.Subtract(span);
        return (this.LastActivityDate.ToUniversalTime() > time);
    }
}

Phil

Lee Dumond · March 20th, 2009, 10:30 AM

In practice, there is no need to have a backing field for a property whose value is directly calculated from the value of another property which has a backing field.

In this case, the value of IsOnline is directly derived from the value of LastActivityDate. Since the backing field for LastActivityDate (_LastActivityDate) contains all the information required to derive IsOnline, having a backing field for IsOnline would be redundant.

Hope that makes sense.

P.S. Like Philip, I'm not sure what you're trying to achieve either. But, the way to modify the value of IsOnline would be to do so indirectly with the Membership.UpdateUser method.