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.
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.
|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.
Direct Show .NET | C API | Filters
Media Foundation .NET | C API | Transforms