UsbQueryNumberDevices

Description

Obtains the total number of currently attached USB devices.

Syntax

ulrc = UsbQueryNumberDevices(pulNumDev)

Parameters

pulNumDev

the address of the variable to receive the Total Number.

Return Code

0x0000 - NO_ERROR

Errors

0x0057 - ERROR_INVALID_PARAMETER
0x1B58 - USB_NOT_INIT
0xFF13 - ERROR_I24_INVALID_PARAMETER
0xFF1F - ERROR_GEN_FAILURE
0xFF57 - ERROR_INVALID_PARAMETER

Example Code

//Code Snippet - UsbQueryNumberDevices
{
  APIRET ulrc;
  PULONG pulNumDev;
  ULONG ulNumDev;

  pulNumDev = &ulNumDev;
  ulrc = UsbQueryNumberDevices(pulNumDev);
  printf("\nUsbQueryNumberDevices - ulrc: 0x%04X (%hu)",ulrc,ulrc);
  if (!ulrc) //success
  {
    printf(" - NumberDevices: %hu",ulNumDev);
  }
}