Monitoring Drives with WMI

Question

I am trying to monitor drives a local PC. I am interested in two events: when the drive is connected (USB drive, CD-ROM, Network Drive, etc.) and disconnected. I wrote a quick proof of concept using the ManagementOperationObserver and it partially works. Right now (with the code below), I am getting all sort of events. I would like to get only events when a drive is connected and disconnected. Is there a way to specify this in the Wql Query?

Thanks!

    private void button2_Click(object sender, EventArgs e)
    {
        t = new Thread(new ParameterizedThreadStart(o =>
        {
            WqlEventQuery q;
            ManagementOperationObserver observer = new ManagementOperationObserver();

            ManagementScope scope = new ManagementScope("root\\CIMV2");
            scope.Options.EnablePrivileges = true;

            q = new WqlEventQuery();
            q.EventClassName = "__InstanceOperationEvent";
            q.WithinInterval = new TimeSpan(0, 0, 3);
            q.Condition = @"TargetInstance ISA 'Win32_LogicalDisk' ";
            w = new ManagementEventWatcher(scope, q);

            w.EventArrived += new EventArrivedEventHandler(w_EventArrived);
            w.Start();
        }));

        t.Start();
    }

    void w_EventArrived(object sender, EventArrivedEventArgs e)
    {
        //Get the Event object and display its properties (all)
        foreach (PropertyData pd in e.NewEvent.Properties)
        {
            ManagementBaseObject mbo = null;
            if ((mbo = pd.Value as ManagementBaseObject) != null)
            {
                this.listBox1.BeginInvoke(new Action(() => listBox1.Items.Add("--------------Properties------------------")));
                foreach (PropertyData prop in mbo.Properties)
                    this.listBox1.BeginInvoke(new Action<PropertyData>(p => listBox1.Items.Add(p.Name + " - " + p.Value)), prop);
            }
        }
    }

Answer 1

You're almost there. To distinguish between a drive being connected to a machine and a drive being removed, you need to check whether e.NewEvent is an instance of __InstanceCreationEvent or __InstanceDeletionEvent respectively. Something along these lines:

ManagementBaseObject baseObject = (ManagementBaseObject) e.NewEvent;

if (baseObject.ClassPath.ClassName.Equals("__InstanceCreationEvent"))
    Console.WriteLine("A drive was connected");
else if (baseObject.ClassPath.ClassName.Equals("__InstanceDeletionEvent"))
    Console.WriteLine("A drive was removed");

Furthermore, you can also get the Win32_LogicalDisk instance via the TargetInstance property.

ManagementBaseObject logicalDisk = 
               (ManagementBaseObject) e.NewEvent["TargetInstance"];

Console.WriteLine("Drive type is {0}", 
                  logicalDisk.Properties["DriveType"].Value);