Detecting user name from process ID

WinApi.cs

/*
How to get the username from process id in WINDOWS.

With the help from stackoverflow:

https://stackoverflow.com/questions/3172392/detecting-user-name-from-process-id
https://stackoverflow.com/questions/777548/how-do-i-determine-the-owner-of-a-process-in-c
*/

using System;
using System.Runtime.InteropServices;
using System.Security.Principal;

namespace ConsoleApp5
{
  public static class WinApi
  {
    public static string GetProcessOwnerByID(int processId)
    {
      IntPtr processHandle = IntPtr.Zero;
      IntPtr tokenHandle = IntPtr.Zero;
      try
      {
        processHandle = OpenProcess(PROCESS_QUERY_INFORMATION, false, processId);
        if (processHandle == IntPtr.Zero)
          return "NO ACCESS";

        OpenProcessToken(processHandle, TOKEN_QUERY, out tokenHandle);
        using (WindowsIdentity wi = new WindowsIdentity(tokenHandle))
        {
          string user = wi.Name;
          return user.Contains(@"\") ? user.Substring(user.IndexOf(@"\") + 1) : user;
        }
      }
      finally
      {
        if (tokenHandle != IntPtr.Zero) CloseHandle(tokenHandle);
        if (processHandle != IntPtr.Zero) CloseHandle(processHandle);
      }
    }

    [DllImport("kernel32.dll")]
    public static extern IntPtr OpenProcess(uint dwDesiredAccess, bool bInheritHandle, int dwProcessId);

    [DllImport("advapi32.dll", SetLastError = true)]
    private static extern bool OpenProcessToken(IntPtr ProcessHandle, uint DesiredAccess, out IntPtr TokenHandle);

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool CloseHandle(IntPtr hObject);

    private const UInt32 STANDARD_RIGHTS_REQUIRED = 0x000F0000;
    private const UInt32 SYNCHRONIZE = 0x00100000;

    private const UInt32 PROCESS_TERMINATE = 0x0001;
    private const UInt32 PROCESS_CREATE_THREAD = 0x0002;
    private const UInt32 PROCESS_SET_SESSIONID = 0x0004;
    private const UInt32 PROCESS_VM_OPERATION = 0x0008;
    private const UInt32 PROCESS_VM_READ = 0x0010;
    private const UInt32 PROCESS_VM_WRITE = 0x0020;
    private const UInt32 PROCESS_DUP_HANDLE = 0x0040;
    private const UInt32 PROCESS_CREATE_PROCESS = 0x0080;
    private const UInt32 PROCESS_SET_QUOTA = 0x0100;
    private const UInt32 PROCESS_SET_INFORMATION = 0x0200;
    private const UInt32 PROCESS_QUERY_INFORMATION = 0x0400;
    private const UInt32 PROCESS_SUSPEND_RESUME = 0x0800;
    private const UInt32 PROCESS_ALL_ACCESS = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0xFFF;

    private const UInt32 TOKEN_ASSIGN_PRIMARY = 0x0001;
    private const UInt32 TOKEN_DUPLICATE = 0x0002;
    private const UInt32 TOKEN_IMPERSONATE = 0x0004;
    private const UInt32 TOKEN_QUERY = 0x0008;
    private const UInt32 TOKEN_QUERY_SOURCE = 0x0010;
    private const UInt32 TOKEN_ADJUST_PRIVILEGES = 0x0020;
    private const UInt32 TOKEN_ADJUST_GROUPS = 0x0040;
    private const UInt32 TOKEN_ADJUST_DEFAULT = 0x0080;
    private const UInt32 TOKEN_ADJUST_SESSIONID = 0x0100;
  }
}