#include "lttwn.h"
L_INT pEXT_CALLBACK YourFunction(hSession, pResConfig, pUserData)
| 
 HTWAINSESSION hSession;  | 
 /* handle to an existing TWAIN session */  | 
| 
 pFASTCONFIG pResConfig;  | 
 /* pointer to a FASTCONFIG structure */  | 
| 
 L_VOID *pUserData;  | 
 /* pointer to additional parameters */  | 
Called for each configuration test. The address of this callback is passed as an argument to L_TwainFindFastConfig.
| 
 Parameter  | 
 Description  | 
| 
 hSession  | 
 Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession function.  | 
| 
 pResConfig  | 
 Pointer to a FASTCONFIG structure that contains the scan configuration that is currently being tested.  | 
| 
 pUserData  | 
 A 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. (This is the same pointer that you pass in the pUserData parameter of L_TwainFindFastConfig.)  | 
| 
 
  | 
 Keep in mind that this is a void pointer, which must be cast to the appropriate data type within your callback function.  | 
Returns
| 
 SUCCESS  | 
 The function was successful.  | 
| 
 SUCCESS_ABORT  | 
 Abort the testing configuration.  | 
Comments
If you return SUCCESS, then the scan configuration testing process will be continued, otherwise, the process will be stopped.
Required DLLs and Libraries
| 
 LTTWN For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.  | 
See Also
Example
For an example, refer to L_TwainFindFastConfig.