Eran Kampf
Eran Kampf
2 min read

Getting the Full Name of the Current User

One of the developers in our team recently encountered a problem of getting the display name of the current user.
The .NET framework exposes the user name through Environment.UserName or System.Security.Principal.WindowsIdentity.GetCurrent().Name but there’s no API to get the user’s display name.
The simplest implementation to get the display name would be using DirectoryServices:

public static string GetUserFullName(string domain, string userName) {
  DirectoryEntry userEntry = new DirectoryEntry("WinNT://" + domain + "/" + userName + ",User");
  return (string)userEntry.Properties["fullname"].Value;

The above method can be called with the current user name and domain to get the user’s fullname:

GetUserFullName(Environment.UserDomainName, Environment.UserName)

This method will fail to provide a correct result of the fullname property is not configured in ActiveDirectory.
Windows provide an unmanaged API called GetUserNameEx that can be called using interop:

  /// <summary>
  /// Wraps the GetUserNameEx API in secur32.dll
  /// </summary>  /// <see>
  /// </see>
  public static class GetUserNameExUtil {
   #region Interop Definitions
   public enum EXTENDED_NAME_FORMAT {
    NameUnknown = 0,
    NameFullyQualifiedDN = 1,
    NameSamCompatible = 2,
    NameDisplay = 3,
    NameUniqueId = 6,
    NameCanonical = 7,
    NameUserPrincipal = 8,
    NameCanonicalEx = 9,
    NameServicePrincipal = 10,
    NameDnsDomain = 12,
   [System.Runtime.InteropServices.DllImport("secur32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]
   public static extern int GetUserNameEx(int nameFormat, StringBuilder userName, ref int userNameSize);

   public static string GetUserName(EXTENDED_NAME_FORMAT nameFormat) {
    if (Environment.OSVersion.Platform != PlatformID.Win32NT) {
     return null;
    StringBuilder userName = new StringBuilder(1024);
    int userNameSize = userName.Capacity;
    if (GetUserNameEx((int) nameFormat, userName, ref userNameSize) != 0) {
     string[] nameParts = userName.ToString().Split('\\');
     return nameParts[0];
    return null;
   public static string GetUserFullName() {
    return GetUserName(EXTENDED_NAME_FORMAT.NameDisplay);

Just call GetUserNameExUtil.GetUserDisplayName() to get the user’s display name…