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   Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits.  | 
#include "lttwn.h"
L_INT pEXT_CALLBACK YourFunction (hSession, pCapability, pUserData)
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 HTWAINSESSION hSession;  | 
 /* handle to an existing TWAIN session */  | 
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 pTW_CAPABILITY pCapability;  | 
 /* pointer to a structure */  | 
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 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.
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 Parameter  | 
 Description  | 
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 hSession  | 
 Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession function.  | 
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 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/.  | 
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 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.)  | 
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  | 
 Keep in mind that this is a void pointer, which must be cast to the appropriate data type within your callback function.  | 
Returns
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 SUCCESS  | 
 The function was successful.  | 
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 SUCCESS_ABORT  | 
 The callback wants to abort the saving procedure.  | 
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 SUCCESS_DELETE  | 
 Abort saving procedure and delete the file.  | 
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 < 1  | 
 An error occurred. Refer to Return Codes.  | 
Comments
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
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 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
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 Functions:  | 
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 Topics:  | 
Example
For an example, refer to L_TwainTemplateDlg.