WMI classes reference

问题:

I have the following problem: I want to get the the logged in user with a WMI class. So I tried this:

    try
    {
        ManagementObjectSearcher searcher = new ManagementObjectSearcher("root\\CIMV2", "SELECT * FROMWin32_LoggedOnUser");
        foreach (ManagementObject queryObj in searcher.Get())
        {
            accounttype += queryObj["Antecedent"];
        }
    }
    catch
    {
        accounttype = "error";
    }

But this don't work because the queryObj returns a reference to Win32_Account! I have no Idea how I can read the values of this Win32_Account reference!

BTW, I know there are other ways ( like Environment.UserName, but I want to generally understand these reverences!

Thanks!

回答1:

The Antecedent and Dependent properties of the Win32_LoggedOnUser WMI class returns a WMI Object Path, which is a unique id for a WMI class instance, you can access the data of to this class creating a instance to the ManagementObject object and then setting the property Path obtained from a ManagementPath object.

Try this sample

using System;
using System.Collections.Generic;
using System.Management;
using System.Text;

namespace GetWMI_Info
{
    class Program
    {

        static void Main(string[] args)
        {
            try
            {
                ManagementScope Scope;
                Scope = new ManagementScope(String.Format("\\\\{0}\\root\\CIMV2", "localhost"), null);

                Scope.Connect();
                ObjectQuery Query = new ObjectQuery("SELECT * FROM Win32_LoggedOnUser");
                ManagementObjectSearcher Searcher = new ManagementObjectSearcher(Scope, Query);

                foreach (ManagementObject WmiObject in Searcher.Get())
                {
                    //Console.WriteLine("{0,-35} {1,-40}","Antecedent",WmiObject["Antecedent"]);// Reference
                    //Console.WriteLine("{0,-35} {1,-40}","Dependent",WmiObject["Dependent"]);// Reference
                    ManagementObject oAntecedent = new ManagementObject();
                    ManagementPath ObjectPath = new ManagementPath((String)WmiObject["Antecedent"]);//Win32_Account 
                    oAntecedent.Path = ObjectPath;
                    oAntecedent.Get();

                    Console.WriteLine("{0,-35} {1,-40}", "Caption", oAntecedent["Caption"]);// String
                    Console.WriteLine("{0,-35} {1,-40}", "Description", oAntecedent["Description"]);// String
                    Console.WriteLine("{0,-35} {1,-40}", "Domain", oAntecedent["Domain"]);// String
                    //Console.WriteLine("{0,-35} {1,-40}", "InstallDate", ManagementDateTimeConverter.ToDateTime((string)WmiObject["InstallDate"]));// Datetime
                    Console.WriteLine("{0,-35} {1,-40}", "LocalAccount", oAntecedent["LocalAccount"]);// Boolean
                    Console.WriteLine("{0,-35} {1,-40}", "Name", oAntecedent["Name"]);// String
                    Console.WriteLine("{0,-35} {1,-40}", "SID", oAntecedent["SID"]);// String
                    Console.WriteLine("{0,-35} {1,-40}", "SIDType", oAntecedent["SIDType"]);// Uint8
                    Console.WriteLine("{0,-35} {1,-40}", "Status", oAntecedent["Status"]);// String
                    Console.WriteLine();    
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(String.Format("Exception {0} Trace {1}",e.Message,e.StackTrace));
            }
            Console.WriteLine("Press Enter to exit");
            Console.Read();
        }
    }
}