查詢登入者的帳號

曾經看過國外有人是使用 api 的方式 Get Current Username
http://www.developerfusion.com/code/4409/get-current-username-in-vbnet/
    Declare Function GetUserName Lib "advapi32.dll" Alias _
       "GetUserNameA" (ByVal lpBuffer As String, _
       ByRef nSize As Integer) As Integer
    Public Function GetUserName() As String
        Dim iReturn As Integer
        Dim userName As String
        userName = New String(CChar(" "), 50)
        iReturn = GetUserName(userName, 50)
        GetUserName = userName.Substring(0, userName.IndexOf(Chr(0)))
    End Function

.net 底下就不用那麼麻煩了
Environment.UserName  '一行搞定

請參考MSDN Library / Environment 類別