Enumerating Users using WMI.NET and C#

Recently, I had to get all the user names in my local machine. I was searching for a proper method and was really hard to get one. I knew I have to use WMI, but the biggest obstacle was of combining different WMI queries to get the result 🙂

The WMI classes that immediately came into my mind were,

• Win32_Account
• Win32_UserAccount
• Win32_Group
• Win32_GroupUser

Each of the classes have their own use. However, Win32_Account forms the main class and other classes derive Win32_Account

So, to get all User Accounts, you could just query,

“select * from Win32_UserAccount where Domain=’YOURDOMAIN'”

And to get all Groups, you could just query,

“select * from Win32_GroupUser where Domain=’YOURDOMAIN'”

So, using C#,

For User accounts,

public static void GetUsers()
{
            SelectQuery sQuery = new SelectQuery("Win32_UserAccount","Domain='CHAKS-PC'");

            try
            {
                ManagementObjectSearcher mSearcher = new ManagementObjectSearcher(sQuery);

                Console.WriteLine("User Accounts");
                Console.WriteLine("");

                foreach (ManagementObject mObject in mSearcher.Get())
                { 
                    Console.WriteLine(mObject["Name"]);              
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }

            Console.ReadKey();
 }

And for Groups,

public static void GetGroups()
 {
            SelectQuery sQuery = new SelectQuery("Win32_Group", "Domain='CHAKS-PC'");

            try
            {
                ManagementObjectSearcher mSearcher = new ManagementObjectSearcher(sQuery);

                Console.WriteLine("Groups");
                Console.WriteLine("");

                foreach (ManagementObject mObject in mSearcher.Get())
                {
                    Console.WriteLine(mObject["Name"]);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }

            Console.ReadKey();
 }

Now to get Users corresponding to a particular group, we need to query Win32_GroupUser and there comes the trick 😉

The Win32_GroupUser is an association class and relates a group and the account to which that is a member of that group.

So, now our query changes to,

“select * from Win32_GroupUser where GroupComponent='”‘Win32_Group.Domain=’domain-name’,Name=’group-name””‘”

And our C# code changes to,

public static void GetUsers(String DomainName, String GroupName)
{
            #region Build WMI query using SelectQuery
            ///<summary>
            /// Alternate method for building query
            /// Which I think is better approach
            ///</summary>
            StringBuilder sBuilder = new StringBuilder("GroupComponent=");
            sBuilder.Append('"');
            sBuilder.Append("Win32_Group.Domain=");
            sBuilder.Append("'");
            sBuilder.Append(DomainName);
            sBuilder.Append("'");
            sBuilder.Append(",Name=");
            sBuilder.Append("'");
            sBuilder.Append(GroupName);
            sBuilder.Append("'");            
            sBuilder.Append('"');
            SelectQuery sQuery = new SelectQuery("Win32_GroupUser", sBuilder.ToString());
            #endregion           

            ///<summary>
            /// Execute the query
            /// Construct a ManagementPath from the PartComponent and check for ClassName
            /// and extract the UserName
            /// Depending on which method you used to build the query,
            /// pass the String or SelectQuery object to ManagementObjectSearcher
            ///</summary>
            try
            {
                ManagementObjectSearcher mSearcher = new ManagementObjectSearcher(sQuery);

                foreach (ManagementObject mObject in mSearcher.Get())
                {
                    ManagementPath path = new ManagementPath(mObject["PartComponent"].ToString());

                    if (path.ClassName == "Win32_UserAccount")
                    {
                        String[] names = path.RelativePath.Split(',');
                        Console.WriteLine(names[1].Substring(names[1].IndexOf("=") + 1).Replace('"', ' ').Trim());
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }

            Console.ReadKey();
}

You can download the source code from here