using System;
using System.Runtime.InteropServices;

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;//域控中的需要用:Interactive = 2

    private bool disposed;

    /// <summary>
    /// 登录
    /// </summary>
    /// <param name="sUsername">用户名</param>
    /// <param name="sDomain">域名,如果不在域中就使用机器IP地址</param>
    /// <param name="sPassword">密码</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);
    }

}