UInt32 GetUserName([MarshalAs(UnmanagedType.BStr)][Out] out string sUserName);

static extern bool GetUserName(System.Text.StringBuilder sb, ref Int32 length);

<DllImport("advapi32.dll", EntryPoint:="GetUserNameW", SetLastError:=True)> _

Public Function GetUserName(<MarshalAs(UnmanagedType.LPTSTR)>sb As System.Text.StringBuilder, _

Declare Function GetUserName Lib "advapi32.dll" Alias "GetUserNameA" (ByVal lpBuffer As String, ByRef nMax As Integer) As Boolean

namespace GetUserNameExample

        static extern bool GetUserName(StringBuilder lpBuffer, ref int nSize);    

            GetUserName(Buffer, ref nSize);

Namespace GetUserNameExample

        <DllImport("advapi32.dll", EntryPoint:="GetUserNameA", SetLastError:=True)> _

        Public Function GetUserName(<MarshalAs(UnamagedType.LPTSTR)>System.Text.StringBuilder sb, _

            GetUserName(Buffer, nSize)

rc = GetUserName(xstr,max)

public static extern bool GetUserName(System.Text.StringBuilder sb, ref Int32 length);

[Advapi32.util]::GetUserName($str,[ref]$size) |Out-Null

  // Pseudo-name format so GetUserNameEx can return the DNS domain name to

    public static String GetUsernameBySessionId(int sessionId)

      // Pseudo-name format so GetUserNameEx can return the DNS domain name to

public static extern byte GetUserNameEx (ExtendedNameFormat nameFormat,

Declare Function GetUserNameEx Lib "secur32.dll" (nameFormat As Integer, _

      public static extern byte GetUserNameEx (int nameFormat, StringBuilder userName, ref int userNameSize);

     if(0 != GetUserNameEx((int)EXTENDED_NAME_FORMAT.NameSamCompatible, userName, ref userNameSize))

  Declare Function GetUserNameExA Lib "secur32.dll" (ByVal nameFormat As Integer, _

' GetUserNameExA for ANSI

' GetUserNameExW for UNICODE

    Public Function GetUserName() As String

    If GetUserNameExA(EXTENDED_NAME_FORMAT.NameSamCompatible, UserName, userNameSize) <> 0 Then