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RegisterDeviceNotification(), how to capture the messages?

Hello,

I'm trying to use the function RegisterDeviceNotification to handle when a USB device attaches or removes.

I have made my own class, CUSB, which contain all my USB handlings. CUSB is not a form class. I want to call CUSB::MyFunction on device change. My first question is, what should I send as HANDLE to RegisterDeviceNotification? When using TForm classes, which contain a HANDLE, they just send this->Handle; But I do not have such a HANDLE. Can I use just "this" as a HANDLE?

DeviceNotificationHandle = RegisterDeviceNotification(this, &DevBroadcastDeviceInterface, DEVICE_NOTIFY_WINDOW_HANDLE);

The other question is: how do I set CUSB::MyFunction to called when a WM_DEVICECHANGE message occurs?

Regards
Eimund Smestad

ASKER CERTIFIED SOLUTION

jkr

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Eimund

ASKER

I see. Then what I ask is not possible. My class have to be a form? If so this is not a solution for me.

Is there a way to use the HANDLE to my USB device to check if it is still attached or detached?

Eimnund Smestad

jkr

Well, your form does for sure have a window handle, ant that should clear everything up...

Eimund

ASKER

CUSB is not of TForm class, and I don't want it to be either!

My question is if this is possible for a regular class?

Eimund Smestad

jkr

But you need some form to process the messages, since callback functions are not allowed for that notification...

Eimund

ASKER

Yes it is what I realized, I thought initialy that it was a callback function. But since it is not, then my current solution is more appealing to me. I have a function which I can check for a valide respons, the only drawback is that I need a timer to pull this function.

But thank you very much for the clarification.

Eimund Smestad