How to get vendor id and product id of a USB device on windows system

[squidge]

DevicePath will be WCHAR array. You'll need to convert it to something like QString before using qDebug() etc. Or you can pass it to CreateFile, then use HidD_GetAttributes to get the above structure filled in.

[newb]

Thank you for the reply dude...

Below is my full source code to get the vendor id and product id from the usb device.

after i run the my qt application i plug the usb device into the system.

but when i print the pDetData->DevicePath;

qDebug ()<<pDetData->DevicePath;

i get the result as 0x4

Whether i have any implementation mistakes in my source code ?

if so please guide me what i am doing wrong..

Have i missed out any other functions ?

Is it possible to get the vendor id and product id from the usb device based on my source code .( my implementation of the code ) ?

kindly find my source code below

Looking for your guidence..

static GUID GUID_DEVINTERFACE_USB_DEVICE = { 0xA5DCBF10L, 0x6530, 0x11D2, { 0x90, 0x1F, 0x00, 0xC0, 0x4F, 0xB9, 0x51, 0xED } };

HANDLE hInfo = SetupDiGetClassDevs(&GUID_DEVINTERFACE_USB_DEVICE, NULL,NULL,DIGCF_PRESENT | DIGCF_INTERFACEDEVICE);

if ( hInfo == INVALID_HANDLE_VALUE )

{

qDebug ()<<"invalid";

}

else

{

qDebug ()<<"valid handle";

SP_DEVINFO_DATA DeviceInfoData;

DeviceInfoData.cbSize = sizeof(SP_DEVINFO_DATA);

SP_INTERFACE_DEVICE_DATA Interface_Info;

Interface_Info.cbSize = sizeof(Interface_Info);

BYTE Buf[1024];

DWORD i;

DWORD InterfaceNumber= 0;

PSP_DEVICE_INTERFACE_DETAIL_DATA pspdidd = (PSP_DEVICE_INTERFACE_DETAIL_DATA)Buf;

for (i=0;SetupDiEnumDeviceInfo(hInfo,i,&DeviceInfoData );i++)

{

DWORD DataT;

LPTSTR buffer = NULL;

DWORD buffersize = 0;

while (!SetupDiGetDeviceRegistryProperty( hInfo,&DeviceInfoData,SPDRP_DEVICEDESC,&DataT,(PBY TE)buffer,buffersize,&buffersize))

{

if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)

{

// Change the buffer size.

if (buffer) LocalFree(buffer);


buffer = (LPTSTR)LocalAlloc(LPTR,buffersize);


}

else

{

// Insert error handling here.

break;

}


qDebug ()<<(TEXT("Device Number %i is: %s\n"),i, buffer);

if (buffer) LocalFree(buffer);


if ( GetLastError()!=NO_ERROR && GetLastError()!=ERROR_NO_MORE_ITEMS )

{

// Insert error handling here.

qDebug ()<<"return false";

}

InterfaceNumber = 0; // this just returns the first one, you can iterate on this

if (SetupDiEnumDeviceInterfaces(hInfo,NULL,&GUID_DEVI NTERFACE_USB_DEVICE,InterfaceNumber,&Interface_Inf o))

{

printf("Got interface");

DWORD needed;

pspdidd->cbSize = sizeof(*pspdidd);

SP_DEVICE_INTERFACE_DETAIL_DATA *pDetData = NULL;

DWORD dwDetDataSize = sizeof (SP_DEVICE_INTERFACE_DETAIL_DATA) + 256;

SetupDiGetDeviceInterfaceDetail(hInfo, &Interface_Info, pDetData,dwDetDataSize, NULL,&DeviceInfoData);


qDebug ()<<pDetData->DevicePath;


//qDebug ()<<QString::fromWCharArray(pDetData->DevicePath);

}

else

{

printf("\nNo interface");

//ErrorExit((LPTSTR) "SetupDiEnumDeviceInterfaces");

if ( GetLastError() == ERROR_NO_MORE_ITEMS) printf(", since there are no more items found.");

else printf(", unknown reason.");

}


// Cleanup

SetupDiDestroyDeviceInfoList(hInfo);

qDebug ()<<"return true";



}

}

}

[squidge]

As I said above, the reason is because DevicePath will be WCHAR array.

[newb]

Even when i try to convert it to QString my application gets crashed.

i used like below

qDebug ()<<QString:::fromWCharArray ( pDetData->DevicePath );

Any helps

[squidge]

Yes, because you are still passing a NULL pointer. Read my code fragment again.

[newb]

hi ..
Thank you...i have corrected my code as you said.
included these codes...
SP_DEVICE_INTERFACE_DETAIL_DATA *pDetData = NULL;

DWORD dwDetDataSize = sizeof (SP_DEVICE_INTERFACE_DETAIL_DATA) + 256;

pDetData = (SP_DEVICE_INTERFACE_DETAIL_DATA*) malloc (dwDetDataSize);

pDetData->cbSize = sizeof (SP_DEVICE_INTERFACE_DETAIL_DATA);

now ..

qDebug ()<<QString::fromWCharArray ( pDetData->DevicePath );
the above print statement returns the below
"\\?\usb#vid_04f2&pid_0111#5&1ba5a77f&0&2#{a5dcbf1 0-6530-11d2-901f-00c04fb951ed}"
but it seems to be for usb keyboard.
i want to get the usb device which i plugged...
how can i get it..
Looking for some guidence...
Thank you

[squidge]

then look at post #8 in this thread. Since you re-asked your question in post #9, ignoring my post, I assumed you wanted a list of USB devices, not the one that got plugged in.

[newb]

sorry for the confusion..

even if it gives the list of usb devices means ..why it displays only one ( usb keyboard )...

why it doesnot display my usb modem which is plugged ...

please help me up.

[squidge]

You'll need to step through the code and see where it exits your loop. Maybe one of the calls fail. You also seem to have some unnecessary code there, although it is difficult to read.

[newb]

. . . .

[newb]

Hi...

the application comes and prints this

"\\?\usb#vid_04f2&pid_0111#5&1ba5a77f&0&2#{a5dcbf1 0-6530-11d2-901f-00c04fb951ed}"

again it goes to while loop ....

here it gets breaked in the else statement...

if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
 {
            // Change the buffer size.
           if (buffer) LocalFree(buffer);
 
           buffer = (LPTSTR)LocalAlloc(LPTR,buffersize);
 
}
 
else
{
     qDebug ()<<"Here it quits the application";
 
    // Insert error handling here.
   break;
 
 }

if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
 {
            // Change the buffer size.
           if (buffer) LocalFree(buffer);

           buffer = (LPTSTR)LocalAlloc(LPTR,buffersize);

}

else
{
     qDebug ()<<"Here it quits the application";

    // Insert error handling here.
   break;

 }

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Any ideas in this....

[newb]

Hello Qt Experts....

Kindly guide me on my problem...

[squidge]

Say, did you write that code or copy it from somewhere? As you don't seem to understand how it works?

Secondly, why are you expecting the call to fail with an insufficient buffer error code? Surely having a sufficient buffer size is a good thing, rather than a bad one?

[newb]

Actually i want to get the vendor id and product id of a usb device which is get plugged....

i searched for Qt related implementation but i don seem to get any sample source code .

So i searched forums and links for that..

so i referred the links and followed the code they have used ..

Any ideas

[squidge]

Ok, well if you use what I say in post #8, that will tell you when a device is plugged/unplugged, which seems to be what you want.

If you google it, there will no doubt be lots of other people who have used it, and thus example code.