The properties and methods exposed by the My.User object provide access to the information about the current user. The meaning of "current user" differs slightly between Windows and Web applications. In a Windows application, the current user is the user who runs the application. In a Web application, the current user is the user who accesses the application.

The My.User property also provides access to the IPrincipal for the current user. A principal object represents the user's security context, including that user's identity and any roles to which the user belongs.

For Windows applications, this property provides the same functionality as the CurrentPrincipal property. For Web applications, this property provides the same functionality as the User property of the object returned by the Current property.

Note
For Windows applications, only projects built on the Windows Application template initialize the My.User object by default. In all other Windows project types, you must initialize the My.User object by calling the My.User.InitializeWithWindowsUser Method explicitly or by assigning a value to CurrentPrincipal.

Note
The My.User object cannot report information about the current Windows user when run under Windows 95 and Windows 98 because those operating systems do not support the concept of a logged-on user. You must implement custom authentication to use the My.User object on those operating systems. For more information, see Walkthrough: Implementing Custom Authentication and Authorization.

The following table lists examples of tasks involving the My.User object.

This example checks if the application is using Windows or custom authentication, and uses that information to parse the My.User.Name property.

Function GetUserName() As String
    If TypeOf My.User.CurrentPrincipal Is _
    Security.Principal.WindowsPrincipal Then
        ' The application is using Windows authentication.
        ' The name format is DOMAIN\USERNAME.
        Dim parts() As String = Split(My.User.Name, "\")
        Dim username As String = parts(1)
        Return username
    Else
        ' The application is using custom authentication.
        Return My.User.Name
    End If
End Function

Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)

Reference