References ▼
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.
#include "lttwn.h"
L_INT pEXT_CALLBACK YourFunction (hSession, pCapability, pUserData)
Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession or L_TwainInitSession2 function.
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 specification.
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.
| Value | Meaning |
|---|---|
| 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.
For an example, refer to L_TwainTemplateDlg.