using System;
using System.Collections.Generic;
using System.Text;
using System.Security.PRincipal;
using System.Runtime.InteropServices;

public class Impersonate
{
    #region 模拟
    private WindowsImpersonationContext impersonationContext;

    private const int LOGON32_LOGON_INTERACTIVE = 2;
    private const int LOGON32_PROVIDER_DEFAULT = 0;

    [DllImport("advapi32.dll", CharSet = CharSet.Auto)]
    private static extern int LogonUser(String lpszUserName, String lpszDomain, String lpszPassWord,
                  int dwLogonType, int dwLogonProvider, ref IntPtr phToken);

    [DllImport("advapi32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto, SetLastError = true)]
    private extern static int DuplicateToken(IntPtr hToken, int impersonationLevel, ref IntPtr hNewToken);

    [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern bool RevertToSelf();

    [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
    private extern static bool CloseHandle(IntPtr handle);

    /// <summary>
    /// 模拟一个用户
    /// </summary>
    /// <param name="userName">用户名</param>
    /// <param name="password">密码</param>
    /// <param name="domain">域名/计算机名</param>
    /// <returns>true 模拟成功，false 模拟失败</returns>
    public bool ImpersonateUser(string userName, string password, string domain)
    {
        WindowsIdentity wi;
        IntPtr token = IntPtr.Zero;
        IntPtr tokenDuplicate = IntPtr.Zero;
        if (RevertToSelf())
        {
            if (LogonUser(userName, domain, password,
                        LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, ref token) != 0)
            {
                if (DuplicateToken(token, 2, ref tokenDuplicate) != 0)
                {
                    wi = new WindowsIdentity(tokenDuplicate);
                    impersonationContext = wi.Impersonate();
                    if (impersonationContext != null)
                    {
                        CloseHandle(tokenDuplicate);
                        CloseHandle(token);
                        return true;
                    }
                    else
                    {
                        if (tokenDuplicate != IntPtr.Zero) CloseHandle(tokenDuplicate);
                        if (token != IntPtr.Zero) CloseHandle(token);
                        return false;
                    }
                }
                else
                {
                    if (token != IntPtr.Zero) CloseHandle(token);
                    return false;
                }
            }
            else
                return false;
        }
        else
            return false;
    }

    /// <summary>
    /// 取消模拟
    /// </summary>
    public void UndoImpersonation()
    {
        impersonationContext.Undo();
    }
    #endregion

    #region 关机
    [StructLayout(LayoutKind.Sequential, Pack = 1)]
    private struct TokPriv1Luid
    {
        public int Count;
        public long Luid;
        public int Attr;
    }

    [DllImport("kernel32.dll", ExactSpelling = true)]
    private static extern IntPtr GetCurrentThread();

    [DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]
    private static extern bool OpenThreadToken(IntPtr h, int acc, bool openAsSelf, ref IntPtr phtok);

    [DllImport("advapi32.dll", SetLastError = true)]
    private static extern bool LookupPrivilegeValue(string host, string name, ref long pluid);

    [DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]
    private static extern bool AdjustTokenPrivileges(IntPtr htok, bool disall, ref TokPriv1Luid newst,
                 int len, IntPtr prev, IntPtr relen);

    [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
    private static extern bool ExitWindowsEx(int flg, int rea);

    [DllImport("advapi32.dll")]
    private static extern bool InitiateSystemShutdown(string Machinename, string Message,
                  long Timeout, bool ForceAppsClosed, bool RebootAfterShutdown);

    private const int SE_PRIVILEGE_ENABLED = 0x00000002;
    private const int TOKEN_QUERY = 0x00000008;
    private const int TOKEN_ADJUST_PRIVILEGES = 0x00000020;
    private const string SE_SHUTDOWN_NAME = "SeShutdownPrivilege";
    private const int EWX_LOGOFF = 0x00000000;
    private const int EWX_SHUTDOWN = 0x00000001;
    private const int EWX_REBOOT = 0x00000002;
    private const int EWX_FORCE = 0x00000004;
    private const int EWX_POWEROFF = 0x00000008;
    private const int EWX_FORCEIFHUNG = 0x00000010;

    /// <summary>
    /// 关机
    /// </summary>
    /// <returns></returns>
    public bool ShutDown()
    {
        bool result;
        TokPriv1Luid tp;
        //注意:这里用的是GetCurrentThread,而不是GetCurrentProcess
        IntPtr hproc = GetCurrentThread();
        IntPtr htok = IntPtr.Zero;
        //注意:这里用的是OpenThreadToken(打开线程令牌),而不是OpenProcessToken(打开进程令牌)
        result = OpenThreadToken(hproc, TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY,
                           true, ref htok);
        tp.Count = 1;
        tp.Luid = 0;
        tp.Attr = SE_PRIVILEGE_ENABLED;
        result = LookupPrivilegeValue(null, SE_SHUTDOWN_NAME, ref tp.Luid);
        result = AdjustTokenPrivileges(htok, false, ref tp, 0, IntPtr.Zero, IntPtr.Zero);
        result = InitiateSystemShutdown("", "", 60, true, false);
        return result;
    }
    #endregion
}
http://www.cnblogs.com/anjou/archive/2006/11/30/577279.html