Window Service程序中如何获取登陆用户的信息

    在window form程序中， 获取当前用户的信息是很容易的一件事情。然而，在window service中， 如何获取当前活动的（登陆的）用户的信息，.NET 并没有给出一种很容易的方法。多数情况下，用户需要调用底层API以达到此目的。如果想在services中启动一个线程并且运行在当前活动的用户UI界面上，获取当前活动的用户，更是必须的操作。

    在windows底层的api中，提供了以下的方法来满足需求：

    WTSGetActiveConsoleSessionId: 获取当前active User的 session ID。

    CreateProcessAsUser：用当前用户创建一个新的进程。

    下面的程序提供了两个方法，一是获取当前活动的用户包括域名和用户名，二是用当前用户创建一个新的进程。

using System;
using System.Security;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace NS_UserTest
{
    /// <summary>
    /// Class that allows running applications with full admin rights. In
    /// addition the application launched will bypass the Vista UAC prompt.
    /// </summary>
    public class ApplicationLoader
    {
        #region Structures

        [StructLayout(LayoutKind.Sequential)]
        public struct SECURITY_ATTRIBUTES
        {
            public int Length;
            public IntPtr lpSecurityDescriptor;
            public bool bInheritHandle;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct STARTUPINFO
        {
            public int cb;
            public String lpReserved;
            public String lpDesktop;
            public String lpTitle;
            public uint dwX;
            public uint dwY;
            public uint dwXSize;
            public uint dwYSize;
            public uint dwXCountChars;
            public uint dwYCountChars;
            public uint dwFillAttribute;
            public uint dwFlags;
            public short wShowWindow;
            public short cbReserved2;
            public IntPtr lpReserved2;
            public IntPtr hStdInput;
            public IntPtr hStdOutput;
            public IntPtr hStdError;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct PROCESS_INFORMATION
        {
            public IntPtr hProcess;
            public IntPtr hThread;
            public uint dwProcessId;
            public uint dwThreadId;
        }

        #endregion

        #region Enumerations

        enum TOKEN_TYPE : int
        {
            TokenPrimary = 1,
            TokenImpersonation = 2
        }

        enum SECURITY_IMPERSONATION_LEVEL : int
        {
            SecurityAnonymous = 0,
            SecurityIdentification = 1,
            SecurityImpersonation = 2,
            SecurityDelegation = 3,
        }

        enum WTSInfoClass
        {
            InitialProgram,
            ApplicationName,
            WorkingDirectory,
            OEMId,
            SessionId,
            UserName,
            WinStationName,
            DomainName,
            ConnectState,
            ClientBuildNumber,
            ClientName,
            ClientDirectory,
            ClientProductId,
            ClientHardwareId,
            ClientAddress,
            ClientDisplay,
            ClientProtocolType
        } 

        #endregion

        #region Constants

        public const int TOKEN_DUPLICATE = 0x0002;
        public const uint MAXIMUM_ALLOWED = 0x2000000;
        public const int CREATE_NEW_CONSOLE = 0x00000010;

        public const int IDLE_PRIORITY_CLASS = 0x40;
        public const int NORMAL_PRIORITY_CLASS = 0x20;
        public const int HIGH_PRIORITY_CLASS = 0x80;
        public const int REALTIME_PRIORITY_CLASS = 0x100;

        #endregion

        #region Win32 API Imports

        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern bool CloseHandle(IntPtr hSnapshot);

        [DllImport("kernel32.dll")]
        static extern uint WTSGetActiveConsoleSessionId();

        [DllImport("wtsapi32.dll", CharSet = CharSet.Unicode, SetLastError = true), SuppressUnmanagedCodeSecurityAttribute]
        static extern bool WTSQuerySessionInformation(System.IntPtr hServer, int sessionId, WTSInfoClass wtsInfoClass, out System.IntPtr ppBuffer, out uint pBytesReturned);

        [DllImport("advapi32.dll", EntryPoint = "CreateProcessAsUser", SetLastError = true, CharSet = CharSet.Ansi, CallingConvention = CallingConvention.StdCall)]
        public extern static bool CreateProcessAsUser(IntPtr hToken, String lpApplicationName, String lpCommandLine, ref SECURITY_ATTRIBUTES lpProcessAttributes,
            ref SECURITY_ATTRIBUTES lpThreadAttributes, bool bInheritHandle, int dwCreationFlags, IntPtr lpEnvironment,
            String lpCurrentDirectory, ref STARTUPINFO lpStartupInfo, out PROCESS_INFORMATION lpProcessInformation);

        [DllImport("kernel32.dll")]
        static extern bool ProcessIdToSessionId(uint dwProcessId, ref uint pSessionId);

        [DllImport("advapi32.dll", EntryPoint = "DuplicateTokenEx")]
        public extern static bool DuplicateTokenEx(IntPtr ExistingTokenHandle, uint dwDesiredAccess,
            ref SECURITY_ATTRIBUTES lpThreadAttributes, int TokenType,
            int ImpersonationLevel, ref IntPtr DuplicateTokenHandle);

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

        [DllImport("advapi32", SetLastError = true), SuppressUnmanagedCodeSecurityAttribute]
        static extern bool OpenProcessToken(IntPtr ProcessHandle, int DesiredAccess, ref IntPtr TokenHandle);

        #endregion

        public static string GetCurrentActiveUser()
        {
            IntPtr hServer = IntPtr.Zero, state = IntPtr.Zero;
            uint bCount = 0;

            // obtain the currently active session id; every logged on user in the system has a unique session id
            uint dwSessionId = WTSGetActiveConsoleSessionId();
            string domain = string.Empty, userName = string.Empty;

            if (WTSQuerySessionInformation(hServer, (int)dwSessionId, WTSInfoClass.DomainName, out state, out bCount))
            {
                domain = Marshal.PtrToStringAuto(state);
            }

            if (WTSQuerySessionInformation(hServer, (int)dwSessionId, WTSInfoClass.UserName, out state, out bCount))
            {
                userName = Marshal.PtrToStringAuto(state);
            }

            return string.Format("{0}\\{1}", domain, userName);
        }

        /// <summary>
        /// Launches the given application with full admin rights, and in addition bypasses the Vista UAC prompt
        /// </summary>
        /// <param name="applicationName">The name of the application to launch</param>
        /// <param name="procInfo">Process information regarding the launched application that gets returned to the caller</param>
        /// <returns></returns>
        public static bool StartProcessAndBypassUAC(String applicationName, String command, out PROCESS_INFORMATION procInfo)
        {
            uint winlogonPid = 0;
            IntPtr hUserTokenDup = IntPtr.Zero, hPToken = IntPtr.Zero, hProcess = IntPtr.Zero;
            procInfo = new PROCESS_INFORMATION();

            // obtain the currently active session id; every logged on user in the system has a unique session id
            uint dwSessionId = WTSGetActiveConsoleSessionId();

            // obtain the process id of the winlogon process that is running within the currently active session
            Process[] processes = Process.GetProcessesByName("winlogon");
            foreach (Process p in processes)
            {
                if ((uint)p.SessionId == dwSessionId)
                {
                    winlogonPid = (uint)p.Id;
                }
            }

            // obtain a handle to the winlogon process
            hProcess = OpenProcess(MAXIMUM_ALLOWED, false, winlogonPid);

            // obtain a handle to the access token of the winlogon process
            if (!OpenProcessToken(hProcess, TOKEN_DUPLICATE, ref hPToken))
            {
                CloseHandle(hProcess);
                return false;
            }

            // Security attibute structure used in DuplicateTokenEx and CreateProcessAsUser
            // I would prefer to not have to use a security attribute variable and to just 
            // simply pass null and inherit (by default) the security attributes
            // of the existing token. However, in C# structures are value types and therefore
            // cannot be assigned the null value.
            SECURITY_ATTRIBUTES sa = new SECURITY_ATTRIBUTES();
            sa.Length = Marshal.SizeOf(sa);

            // copy the access token of the winlogon process; the newly created token will be a primary token
            if (!DuplicateTokenEx(hPToken, MAXIMUM_ALLOWED, ref sa, (int)SECURITY_IMPERSONATION_LEVEL.SecurityIdentification, (int)TOKEN_TYPE.TokenPrimary, ref hUserTokenDup))
            {
                CloseHandle(hProcess);
                CloseHandle(hPToken);
                return false;
            }

            // By default CreateProcessAsUser creates a process on a non-interactive window station, meaning
            // the window station has a desktop that is invisible and the process is incapable of receiving
            // user input. To remedy this we set the lpDesktop parameter to indicate we want to enable user 
            // interaction with the new process.
            STARTUPINFO si = new STARTUPINFO();
            si.cb = (int)Marshal.SizeOf(si);
            si.lpDesktop = @"winsta0\default"; // interactive window station parameter; basically this indicates that the process created can display a GUI on the desktop

            // flags that specify the priority and creation method of the process
            int dwCreationFlags = NORMAL_PRIORITY_CLASS | CREATE_NEW_CONSOLE;

            // create a new process in the current user's logon session
            bool result = CreateProcessAsUser(hUserTokenDup,        // client's access token
                                            applicationName,        // file to execute
                                            command,                // command line
                                            ref sa,                 // pointer to process SECURITY_ATTRIBUTES
                                            ref sa,                 // pointer to thread SECURITY_ATTRIBUTES
                                            false,                  // handles are not inheritable
                                            dwCreationFlags,        // creation flags
                                            IntPtr.Zero,            // pointer to new environment block 
                                            null,                   // name of current directory 
                                            ref si,                 // pointer to STARTUPINFO structure
                                            out procInfo            // receives information about new process
                                            );

            // invalidate the handles
            CloseHandle(hProcess);
            CloseHandle(hPToken);
            CloseHandle(hUserTokenDup);

            return result; // return the result
        }

    }
}

    下面给出使用此静态方法的事例：

private void RunCommand(object state)
{
    try
    {
        var cmdBatch = state as string;
        if (string.IsNullOrEmpty(cmdBatch))
            return;

        string applicationName = null;
        if (Path.GetExtension(cmdBatch).Equals(".BAT"))
            applicationName = "cmd.exe";

        // launch the application
        ApplicationLoader.PROCESS_INFORMATION procInfo;
        ApplicationLoader.StartProcessAndBypassUAC(applicationName, "\"" +  cmdBatch + "\"", out procInfo);

        // check the process and get the complete or not.
        var process = Process.GetProcessById((int)procInfo.dwProcessId);
        if(process != null)
            process.WaitForExit();
    }
    catch (Exception ex)
    {
        EventLog.WriteEntry(ex.Message, System.Diagnostics.EventLogEntryType.Error);
    }
}

    通过以上的方法，可以看到，当前启动的进程运行在活动用户的界面。