[DllImport("advapi32.dll")]
private static extern bool LogonUser(string lpszUsername, string lpszDomain, string lpszPassword, int dwLogonType, int dwLogonProvider, ref IntPtr phToken);
const int LOGON32_LOGON_INTERACTIVE = 2; //通過網(wǎng)絡驗證賬戶合法性
const int LOGON32_PROVIDER_DEFAULT = 0; //使用默認的Windows 2000/NT NTLM驗證方

public static bool CheckADAccount(string account, string password)
{
    IntPtr tokenHandle = new IntPtr(0);
    tokenHandle = IntPtr.Zero;
    string domainName = "dpbg";
    if (LogonUser(account, domainName, password, LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, ref tokenHandle))
        return true;
    return false;
}

/// <summary>
/// 驗證網(wǎng)域賬號
/// </summary>
/// <param name="account">賬號</param>
/// <param name="password">密碼</param>
/// <param name="domain">網(wǎng)域</param>
/// <param name="name">姓名</param>
/// <returns></returns>
public static bool CheckADAccountNew(string account, string password, string domain, out string name)
{
    name = "";
    using (DirectoryEntry deUser = new DirectoryEntry(@"LDAP://" + domain, account, password))
    {
        DirectorySearcher src = new DirectorySearcher(deUser);
        src.Filter = "(&(&(objectCategory=person)(objectClass=user))(sAMAccountName=" + account + "))";
        src.PropertiesToLoad.Add("cn");
        src.SearchRoot = deUser;
        src.SearchScope = SearchScope.Subtree;
        try
        {
            SearchResult result = src.FindOne();
            if (result != null)//驗證成功
            {
                if (result.Properties["cn"] != null)//依據(jù)實際屬性獲取用戶信息
                {
                    name = result.Properties["cn"][0].ToString();
                }
                return true;
            }
            return false;
        }
        catch
        {
            return false;
        }
    }
}

/// <summary>
/// 驗證網(wǎng)域賬號
/// </summary>
/// <param name="account">賬號</param>
/// <param name="password">密碼</param>
/// <param name="domain">網(wǎng)域</param>
/// <param name="name">姓名</param>
/// <returns></returns>
public static bool CheckADAccountNew(string account, string password, string domain, out string name)
{
    name = "";
    using (var domainContext = new PrincipalContext(ContextType.Domain, domain))
    {
        using (var foundUser = UserPrincipal.FindByIdentity(domainContext, IdentityType.SamAccountName, account))
        {
            if (foundUser == null)
            {
                return false;
            }

            name = foundUser.Name;
            if (domainContext.ValidateCredentials(account, password))
            {
                return true;
            }
            else
            {
                return false;
            }
        }
    }
}