CODEWITHSUNDEEP
c#wmi
Wonko
Wonko

Reputation: 2191

How do I get USB disk drive inserted and removed events in a service without hearing my hard drive being accessed repeatedly on some O/S's?

I use this code in my Windows Service to be notified of USB disk drives being inserted and removed:

WqlEventQuery query = new WqlEventQuery("__InstanceOperationEvent", 
    "TargetInstance ISA 'Win32_LogicalDisk' AND TargetInstance.DriveType=2");
query.WithinInterval = TimeSpan.FromSeconds(1);
_deviceWatcher = new ManagementEventWatcher(query);
_deviceWatcher.EventArrived += new EventArrivedEventHandler(OnDeviceEventArrived);
_deviceWatcher.Start();

It works on XP and Vista, but on XP I can hear the very noticeable sound of the hard drive being accessed every second. Is there another WMI query that will give me the events without the sound effect?

Upvotes: 3

Views: 3630

Answers (3)

Andrew Queisser
Andrew Queisser

Reputation: 1175

Not sure if this applies to your case but we've been using RegisterDeviceNotification in our C# code (which I can't post here) to detect when USB devices are plugged in. There's a handful of native functions you have to import but it generally works well. Easiest to make it work in C++ first and then see what you have to move up into C#.

There's some stuff on koders Code search that appears to be a whole C# device management module that might help:

https://web.archive.org/web/20100329155804/http://www.koders.com/csharp/fidEF5C6B3E2F46BE9AAFC93DB75515DEFC46DB4101.aspx

Upvotes: 2

Mujtaba
Mujtaba

Reputation: 369

try this

using System;
using System.Management;

namespace MonitorDrives
{
class Program
{
    public enum EventType
    {
        Inserted = 2,
        Removed = 3
    }

    static void Main(string[] args)
    {
        ManagementEventWatcher watcher = new ManagementEventWatcher();
        WqlEventQuery query = new WqlEventQuery("SELECT * FROM Win32_VolumeChangeEvent WHERE EventType = 2 or EventType = 3");

        watcher.EventArrived += (s, e) =>
        {
            string driveName = e.NewEvent.Properties["DriveName"].Value.ToString();
            EventType eventType = (EventType)(Convert.ToInt16(e.NewEvent.Properties["EventType"].Value));

            string eventName = Enum.GetName(typeof(EventType), eventType);

            Console.WriteLine("{0}: {1} {2}", DateTime.Now, driveName, eventName);
        };

        watcher.Query = query;
        watcher.Start();

        Console.ReadKey();
    }
}
}

Upvotes: 2

Don Jones
Don Jones

Reputation: 9497

Try looking for the InstanceCreationEvent, which will signal the creation of a new Win32_LogicalDisk instance. Right now you're querying for instance operations, not creations. You should know that the query interval on those events is pretty long - it's possible to pop a USB in and out faster that you'll detect.

Upvotes: 1

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