Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits. |
#include "lttwn.h"
L_INT pEXT_CALLBACK YourFunction (hSession, pCapability, nStatus, pUserData)
HTWAINSESSION hSession; |
/* handle to an existing TWAIN session */ |
pTW_CAPABILITY * pCapability; |
/* pointer to a capability */ |
L_INT nStatus; |
/* indicates success or error code */ |
L_VOID * pUserData; |
/* pointer to additional parameters */ |
Called for each capability being loaded from the template file or saved from the TWAIN source. The address of this callback is passed as an argument L_TwainLoadTemplateFile and L_TwainSaveTemplateFile.
Parameter |
Description |
hSession |
Handle to an existing TWAIN session. |
pCapability |
Pointer to a TW_CAPABILITY structure that contains the capability. For information on this structure, refer to www.twain.org and click on TWAIN Specification. |
nStatus |
When used with L_TwainLoadTemplateFile, nStatus refers to whether pCapability was set successfully. When used with L_TwainSaveTemplateFile, nStatus refers to whether the pCapability was successfully added to the template file. |
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_TwainLoadTemplateFile or L_TwainSaveTemplateFile.) |
|
Keep in mind that this is a void pointer, which must be cast to the appropriate data type within your callback function. |
Returns
TWAIN_SUCCESS |
The function was successful. |
TWAIN_SUCCESS_ABORT |
The callback wants to abort the operation. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
Use this callback to alert the user of any failures in setting a capability when loaded from a template file. You can also use this callback to provide a listing of all capabilities and their possible values found in a template file or being saved to a template file.
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
Functions: |
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Topics: |
Example
For an example, refer to L_TwainSaveTemplateFile.