LTWAINSETPROPERTYCALLBACK

#include "lttwn.h"

L_INT pEXT_CALLBACK YourFunction (hSession, uCap, nStatus, pValue, pUserData)

Called for each property set. The address of this callback is passed as an argument to L_TwainSetProperties.

Parameters

HTWAINSESSION hSession

Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession or L_TwainInitSession2 function.

L_UINT uCap

The capability being set.

L_INT nStatus

This variable holds the value of the error that occurred while the property was being set.

L_VOID * pValue

Pointer to the original value. The user can cast this depending on the type of the property, and modify it.

L_VOID * 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_TwainSetProperties.)

Keep in mind that this is a void pointer, which must be cast to the appropriate data type within your callback function.

Returns

Value Meaning
SUCCESS The function was successful.
TWAIN_SUCCESS_RETRY Retry with the new value in *pValue parameter.
TWAIN_SUCCESS_ABORT Abort the negotiation.

Comments

The user should not free the pValue parameter within this callback.

Required DLLs and Libraries

See Also

Functions

Topics

Example

For an example, refer to L_TwainGetProperties.

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