Query related to Insertion and removal of Plug and Play Devices

[elizabeth1986]

Hello,

Is it possible to detect the insertion and removal of Plug and play devices (for example : keyboard , mouse etc) while the computer is still ON. We wanted to do the above in C#. We tried a couple of WMI classes like win32_Keyboard class, but after manually removing the Keyboard, there was no change in the Property "status" of win32_Keyboard. it showed that the status was OK.
We also tried a piece of code which uses win32_DeviceChangeEvent but that also doesnot seem to work for plug and play devices.
Plaese can u suggest some Solution to this problem.,

[pootle]

Hi,

You could try using the Win32 function RegisterDeviceNotification and test for WM_DEVICECHANGE in WndProc. There are probably some examples of using this in C# - try googling...


HTH.

[Plater]

I tested the following WMI code with:
keyboards
mice
usb->Serial converters
card readers

All worked correctly, firing events.

//Taken from WMICodeCreator
using System;
using System.Management;
using System.Windows.Forms;
 
namespace WMISample
{
    public class WMIReceiveEvent
    {
        public WMIReceiveEvent()
        {
            try
            {
                WqlEventQuery query = new WqlEventQuery(
                    "SELECT * FROM Win32_DeviceChangeEvent");
 
                ManagementEventWatcher watcher = new ManagementEventWatcher(query);
                Console.WriteLine("Waiting for an event...");
 
                watcher.EventArrived += 
                    new EventArrivedEventHandler(
                    HandleEvent);
 
                // Start listening for events
                watcher.Start();
 
                // Do something while waiting for events
                System.Threading.Thread.Sleep(10000);
 
                // Stop listening for events
                watcher.Stop();
                return;
            }
            catch(ManagementException err)
            {
                MessageBox.Show("An error occurred while trying to receive an event: " + err.Message);
            }
        }
 
        private void HandleEvent(object sender,
            EventArrivedEventArgs e)
        {
            Console.WriteLine("Win32_DeviceChangeEvent event occurred.");
        }
 
        public static void Main()
        {
            WMIReceiveEvent receiveEvent = new WMIReceiveEvent();
            return;
        }
 
    }
}
 

[elizabeth1986]

hi....
The Above code only works for USB devices like Pendrives, we tried unplugging the Keyboard but no event is fired.. .
thanks.
.

[Plater]

Oh... huh. You still use a non-usb keyboard. Hmm.
There is probably some Win32_API for that. Although I highly doubt they bothered to keep track of if things were plugged into a ps2, serial or din port.
Although I guess the bios was always able to tell if there was a keyboard or not.

[elizabeth1986]

thanks for the solution , but please can u give some Code in C# which uses Win32_RegisterDeviceNotification method to register a device like Keyboard

[kenobewan]

Please trying writing the code first. The experts on this site are not here to do your work for you. If in doubt, read the posting guidelines. Thanks.

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