public class IdentityScope : IDisposable
{

        // obtains user token
        [DllImport("advapi32.dll", SetLastError = true)]
        static extern bool LogonUser(string pszUsername, string pszDomain, string pszPassword,int dwLogonType, int dwLogonProvider, ref IntPtr phToken);

        // closes open handes returned by LogonUser

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]

        extern static bool CloseHandle(IntPtr handle);


        [DllImport("Advapi32.DLL")]
        static extern bool ImpersonateLoggedOnUser(IntPtr hToken);

        [DllImport("Advapi32.DLL")]
        static extern bool RevertToSelf();

        const int LOGON32_PROVIDER_DEFAULT = 0;

        const int LOGON32_LOGON_NEWCREDENTIALS = 9;//域ò控?中D的?需è要a用?:Interactive = 2

        private bool disposed;

        /// <summary>
        /// 登?录?
        /// </summary>
        /// <param name="sUsername">用?户§名?</param>
        /// <param name="sDomain">域ò名?，?如?果?不?在ú域ò中D就í使1用?机ú器÷IP地?址·</param>
        /// <param name="sPassword">密ü码?</param>
        public IdentityScope(string sUsername, string sDomain, string sPassword)
        {

            // initialize tokens
            IntPtr pExistingTokenHandle = new IntPtr(0);
            IntPtr pDuplicateTokenHandle = new IntPtr(0);
            try
            {

                // get handle to token
                bool bImpersonated = LogonUser(sUsername, sDomain, sPassword,LOGON32_LOGON_NEWCREDENTIALS, LOGON32_PROVIDER_DEFAULT, ref pExistingTokenHandle);
                if (true == bImpersonated)
                {
                    if (!ImpersonateLoggedOnUser(pExistingTokenHandle))
                    {
                        int nErrorCode = Marshal.GetLastWin32Error();
                        throw new Exception("ImpersonateLoggedOnUser error;Code=" + nErrorCode);
                    }
                }
                else
                {
                    int nErrorCode = Marshal.GetLastWin32Error();
                    throw new Exception("LogonUser error;Code=" + nErrorCode);

                }

            }
            finally
            {
                // close handle(s)
                if (pExistingTokenHandle != IntPtr.Zero)

                    CloseHandle(pExistingTokenHandle);

                if (pDuplicateTokenHandle != IntPtr.Zero)

                    CloseHandle(pDuplicateTokenHandle);
            }

        }

        protected virtual void Dispose(bool disposing)
        {

            if (!disposed)
            {
                RevertToSelf();
                disposed = true;
            }

        }

        public void Dispose()
        {
            Dispose(true);
        }

    }

第二个参数是域名，有域名的话写域名，没有域名写目标机器的IP就可以了

using (IdentityScope c = new IdentityScope("administrator", "192.168.0.1", "11111"))
{
  string[] filelist = System.IO.Directory.GetDirectories(@"\\192.168.0.1\folderName");
}