Section 6.5. Test Group Membership of the Current User

6.5. Test Group Membership of the Current User

The .NET Framework has always provided security classes that let you retrieve basic information about the account of the current user. The new My.User object provided by Visual Basic 2005 makes it easier than ever to access this information.

Note: Find out who's using your application, and the groups a mystery user belongs to.

6.5.1. How do I do that?

Applications often need to test who is running the application. For example, you might want to restrict some features to certain groups, such as Windows administrators. You can accomplish this with the My.User object.

The My.User object provides two key properties that return information about the current user. These are:


Returns true if the current user account information is available in the My.User object. The only reason this information wouldn't be present is if you've created a web application that allows anonymous access, or if the current Windows account isn't associated with the application domain.


Returns the current username. Assuming you're using a Windows security policy, this is the Windows account name for the user, in the form ComputerName\UserName or DomainName\UserName.

The My.User object also provides a single method, IsInRole( ). This method accepts the name of a group (as a string) and then returns true if the user belongs to that group. For example, you could use this technique to verify that the current user is a Windows administrator before performing a certain task.

To try this out, use the following console application in Example 6-5, which displays some basic information about the current user and tests if the user is an Administrator.

Note: To check the user and group list for the current computer (or make changes), select Computer management from the Administrative Tools section of the Control Panel. Then, expand the System Tools Local Users and Groups node.
Example 6-5. Testing the current user identity
Module SecurityTest          Sub Main( )         ' Use Windows security. As a result, the User object will         ' provide the information for the currently logged in user         ' who is running the application.         My.User.InitializeWithWindowsUser( )              Console.WriteLine("Authenticated: " & My.User.Identity.IsAuthenticated)         Console.WriteLine("User: " & My.User.Identity.Username)              Console.WriteLine("Administrator: " & My.User.IsInRole("Administrators"))     End Sub      End Module

Here's the sort of output you'll see when you run this test:

Authenticated: True User: FARIAMAT\Matthew Administrator: True

Visual Basic 2005(c) A Developer's Notebook
Visual Basic 2005: A Developers Notebook
ISBN: 0596007264
EAN: 2147483647
Year: 2006
Pages: 123 © 2008-2017.
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