convert parameter from 'const int' to 'void *'

[CHYGO]

i difine a custom message(i want to post it to a driver) #define WM_INTERRUPT WM_USER+100 then i use it as a parameter in the function DeviceIoControl ... ULONG nBytesRead; if (! DeviceIoControl( m_hPCI9054, IOCTL_SET_NOTIFICATION_EVENT, &WM_INTERRUPT, sizeof(WM_INTERRUPT), NULL, 0, &nBytesRead, NULL ) ... it makes an error: ...'DeviceIoControl' : cannot convert parameter 3 from 'const int' to 'void *' how to fix it?

i 've tried ,then i have no regret

[Rajasekharan Vengalil]

You have defined WM_INTERRUPT as a preprocessor symbol. During compilation, the compiler is going to simply replace all occurrences of WM_INTERRUPT with the number 1124. So what you're trying to do essentially, is this - &1124 which of course, does not make sense. Depending on how you have implemented your driver you can choose to pass WM_INTERRUPT directly like so - (void *)WM_INTERRUPT. This will of course, mean that you should not be dereferencing this value from your driver.

-- gleat http://blogorama.nerdworks.in[^] --

[Sarath C]

The parameter should not be constant as per the documentation. Do as follows LONG lData = WM_INTERRUPT; ULONG nBytesRead; if (! DeviceIoControl( m_hPCI9054, IOCTL_SET_NOTIFICATION_EVENT, &lData, sizeof(WM_INTERRUPT), NULL, 0, &nBytesRead, NULL )

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