| LEADTOOLS DICOM C DLL Help > Callback Functions > RECEIVEUNKNOWNCALLBACK | 
#include "ltdic.h"
L_VOID pEXT_CALLBACK Your Function(hNet, nPresentationID, hCS, hDS, pUserData)
| HDICOMNET hNet; | /* a DICOM Network handle */ | 
| L_UCHAR nPresentationID; | /* presentation ID */ | 
| HDICOMDS hCS; | /* command message */ | 
| HDICOMDS hDS; | /* data set */ | 
| L_VOID * pUserData; | /* pointer to additional data */ | 
Notifies a connection that an unknown command was received. This function is available in the PACS Imaging.
| Parameter | Description | 
| hNet | A DICOM Network handle to the peer member of the connection. | 
| nPresentationID | Presentation ID. The presentation ID provides information about both the class type of the data and the transfer syntax to use when transferring the data. | 
| hCS | A DICOM handle that references the command set that contains the actual command message. | 
| hDS | A DICOM handle that contains the actual data. This may be NULL if no data set is included. | 
| pUserData | Void pointer that you can use to access a variable or structure containing data that your callback function needs. This gives you a way to receive data indirectly from the function that uses this callback function. | 
| 
 | Keep in mind that this is a void pointer, which must be cast to the appropriate data type within your callback function. | 
Returns
None.
Comments
A call to this function is generated when an unknown command is received.
To use this callback function, RECEIVEUNKNOWNCALLBACK must be set using L_DicomSetCallback.
Required DLLs and Libraries
| LTDIC For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application | 
Win32, x64
See Also
| Topics: | 
Example
L_VOID EXT_CALLBACK OnReceiveUnknown(HDICOMNET hNet, L_UCHAR nPresentationID, HDICOMDS hCS, HDICOMDS hDS, L_VOID *pUserData)
{
   UNREFERENCED_PARAMETER(hCS);
   UNREFERENCED_PARAMETER(pUserData);
   UNREFERENCED_PARAMETER(hDS);
   UNREFERENCED_PARAMETER(hNet);
   L_TCHAR szOut[800];
   
   wsprintf(szOut, TEXT("Unknown Command Set/Data Set was received, and ignored\nPresentation ID: %d"), nPresentationID);
   MessageBox(NULL, szOut, TEXT("Unknown"), MB_OK);
}