USB RegisterDeviceNotification

[bfoo75]

I've been doing lots of research on controlling USB devices in C# and ran across a few tutorials that seemed good until I started trying to code them. It seems like everyone seems to know how to use the function RegisterDeviceN otification to register the form to recieve WM_DEVICECHANGE messages.

I've gotten as far as importing the function from user32.dll and setting up the device filtering, but I don't really understand the concept of using RegisterDeviceN otification. Can anyone clarify what and where to get the parameters that its asking for?

Here is my code so far:

[code=text]
using System;
using System.Collecti ons.Generic;
using System.Componen tModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows. Forms;
using System.Windows;
using System.Runtime. InteropServices ;
using DeviceManagemen tDeclarations;


namespace USBDevice
{

public partial class Form1 : Form
{
public const int WM_DEVICECHANGE = 0x219;

public Form1()
{
InitializeCompo nent();
RegisterDeviceN otification(thi s.Handle, ?NotificationFi lter?, ?Flags?);

}
protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
case WM_DEVICECHANGE :
{
MessageBox.Show (m.ToString());
break;
}

}

base.WndProc(re f m);
}
[DllImport("user 32.dll", CharSet = CharSet.Auto)]
static public extern IntPtr RegisterDeviceN otification(Int Ptr hRecipient, IntPtr NotificationFil ter, int Flags);

}

}
[/code]

[Plater]

Hmm, I was pretty sure I got that notification just fine without doing any registering.

I will check though.
EDIT:
Just checked, yup I get that message regardless of focus or anything and I didn't need to register for it.

[bfoo75]

Huh... well I feel stupid. How come all these tutorials make out that you have to register the device notification?

I think last time I had it compilable I was using a different filter for the message. Thanks for the clear-up tho!

[Plater]

I should alert you that DeviceNotify isn't as usefull as you would hope. I only found it really usefull for when a USB->SerialPort was added/removed, or some kind of mass storage usb device was added/removed (i.e. thumbdrive, external harddrive, etc)

[nuno1707]

I've been doing the same (some research on monitoring added/removed of mass storage device in C# ) but sa new in C# I don't know what to do!

Could you clarify it or post you Code?

[Plater]

Have a look here:

http://msdn.microsoft.com/en-us/library/aa363480(VS.85).aspx