What is the Difference between USb Root Hub and USB Composite Device?

Question

I am Developing an application where I need to fetch VID and PID of all the Current USB Devices Connected to the Computer.

But I am just getting VID and PID number of my Headphone that is attached to my Computer. and not getting for Mouse and Keyboard.

My Code works like this:-

static List<USBDeviceInfo> GetUSBDevices()
    {
        List<USBDeviceInfo> devices = new List<USBDeviceInfo>();

        ManagementObjectCollection collection;
        using (var searcher = new ManagementObjectSearcher(@"Select * From Win32_USBHub"))
            collection = searcher.Get();

        foreach (var device in collection)
        {
            devices.Add(new USBDeviceInfo(
            (string)device.GetPropertyValue("DeviceID"),
            (string)device.GetPropertyValue("PNPDeviceID"),
            (string)device.GetPropertyValue("Description")
            ));
        }

        collection.Dispose();
        return devices;
    }

Main Class

static void Main(string[] args)
    {
       var usbDevices = GetUSBDevices();
       foreach (var usbDevice in usbDevices)
       {
        Console.WriteLine("Device ID: {0}, PNP Device ID: {1}, Description: {2}",
         usbDevice.DeviceID, usbDevice.PnpDeviceID, usbDevice.Description);
       }
      Console.Read();
     }

Now in case of Headphone I am getting Description as USB Composite Device while in Case of other Devices connected to Computer I am getting Description as USB Root Hub

I don't know why I am getting only VID and PID of only Headphone

Please suggest

Thanks in advance.!!

Solution

A hub is a device that other devices are connected to. Root hubs represent the USB controllers on your motherboard.

A composite device is a device that has multiple interfaces; your headphones has two interfaces, for mixer controls and for audio capture.

Normal USB devices are not listed as Win32_USBHub, you have too look into the Dependent entries. See Getting the USB Devices Information using WMI for an example.

Comments

[Dave]

There is no need to show your code (this site is not a programming site) as it's relevant to your question per se.

[miniBill]

The link is broken