如何知道用户帐户是否存在

Question

1. 我如何知道我的Windows操作系统(Vista)上是否存在用户帐户？我需要来自未加入任何域的独立计算机的此信息.

2. 我想知道用户是否属于某个群组,例如是否是"管理员"群组的用户"管理员"部分？

Answer 1

如果System.Security.Principal使用以下代码通过命名空间存在本地帐户,则可以计算出来.

bool AccountExists(string name)
{
    bool bRet = false;

    try
    {
        NTAccount acct = new NTAccount(name);
        SecurityIdentifier id = (SecurityIdentifier)acct.Translate(typeof(SecurityIdentifier));

        bRet = id.IsAccountSid();
    }
    catch (IdentityNotMappedException)
    {
        /* Invalid user account */
    }

    return bRet;
}

现在获得组成员资格稍微困难一些,您可以使用该WindowsPrinciple.IsInRole方法轻松地为当前用户执行此操作(从WindowsIdentify.GetCurrent()方法创建原则).

正如所指出的那样,我认为没有办法在不诉诸PInvoke或WMI的情况下获得任何其他东西.所以这里有一些代码来检查WMI的组成员身份.

bool IsUserInGroup(string name, string group)
{
    bool bRet = false;
    ObjectQuery query = new ObjectQuery(String.Format("SELECT * FROM Win32_UserAccount WHERE Name='{0}' AND LocalAccount=True", name));
    ManagementObjectSearcher searcher = new ManagementObjectSearcher(query);
    ManagementObjectCollection objs = searcher.Get();

    foreach (ManagementObject o in objs)
    {
        ManagementObjectCollection coll = o.GetRelated("Win32_Group");
        foreach (ManagementObject g in coll)
        {
            bool local = (bool)g["LocalAccount"];
            string groupName = (string)g["Name"];

            if (local && groupName.Equals(group, StringComparison.InvariantCultureIgnoreCase))
            {
                bRet = true;
                break;
            }
        }
    }           

    return bRet;
}

Answer 2

我已经尝试过以下代码并且对我来说工作正常..

    public bool IsUserMemberOfGroup(string userName, string groupName)
    {
        bool ret = false;

        try
        {
            DirectoryEntry localMachine = new DirectoryEntry("WinNT://" + Environment.MachineName);
            DirectoryEntry userGroup = localMachine.Children.Find(groupName, "group");

            object members = userGroup.Invoke("members", null);
            foreach (object groupMember in (IEnumerable)members)
            {
                DirectoryEntry member = new DirectoryEntry(groupMember);
                if (member.Name.Equals(userName, StringComparison.CurrentCultureIgnoreCase))
                {
                    ret = true;
                   break;
                }
            }
        }
        catch (Exception ex)
        {
            ret = false;
        }
        return ret;
    }