#include "lttwn.h"
L_INT pEXT_CALLBACK YourFunction (hSession, pCapability, pUserData)
HTWAINSESSION hSession; |
handle to an existing TWAIN session |
pTW_CAPABILITY pCapability; |
pointer to a structure |
L_VOID * pUserData; |
pointer to additional parameters |
Called for each capability supported by a particular TWAIN source, before saving it to a specific template file. The address of this callback is passed as an argument in L_TwainTemplateDlg.
Parameter |
Description |
hSession |
Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession or L_TwainInitSession2 function. |
pCapability |
Pointer to the TW_CAPABILITY structure that references the capability data to save to the specified template file. For more information about TW_CAPABILITY, refer to the TWAIN 1.9 specification from the site http://www.twain.org/. |
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_TwainTemplateDlg.) |
|
Keep in mind that this is a void pointer, which must be cast to the appropriate data type within your callback function. |
SUCCESS |
The function was successful. |
SUCCESS_ABORT |
The callback wants to abort the saving procedure. |
SUCCESS_DELETE |
Abort saving procedure and delete the file. |
< 1 |
An error occurred. Refer to Return Codes. |
The user can only modify the capability data before saving it to the specified template file.
The user should not free the pointer to the TW_CAPABILITY structure within this callback.
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. |