UsbQueryNumberDevices: Difference between revisions

Latest revision as of 20:47, 13 September 2021

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

Remarks

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);
  }
}

Related Functions

@@ Line 1: / Line 1: @@
-Obtains the total number of USB devices currently attached.
+==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==
+x0000 - NO_ERROR
+===Errors===
 <pre>
-ulrc=UsbQueryNumberDevices(*pulNumDev)
+x0057 - ERROR_INVALID_PARAMETER
+x1B58 - USB_NOT_INIT
+xFF13 - ERROR_I24_INVALID_PARAMETER
+xFF1F - ERROR_GEN_FAILURE
+xFF57 - ERROR_INVALID_PARAMETER
 </pre>
-==Parameters==
+==Remarks==
-; pulNumDev :
+==Example Code==
+<pre>
+//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);
+  }
+}
+</pre>
-==Return Code==
+==Related Functions==
-Errors
+* [[UsbQueryDeviceReport]]
- [0000] - NO_ERROR
+* [[UsbQueryDeviceInfo]]
- [0057] - ERROR_INVALID_PARAMETER
+* [[UsbOpen]]
- [1B58] - USB_NOT_INIT (7000)
- [FF13] - ERROR_I24_INVALID_PARAMETER
- [FF1F] - ERROR_GEN_FAILURE
- [FF57] - ERROR_INVALID_PARAMETER
-[[Category:Stub]]
+[[Category:USBCalls]]