L_TwainSetDeviceEventCallback

#include "lttwn.h"

L_LTTWN_API L_INT L_TwainSetDeviceEventCallback(hSession, pfnCallBack, pUserData)

HTWAINSESSION hSession;

handle to an existing TWAIN session

LTWAINDEVICEEVENTCALLBACK pfnCallBack;

callback function

L_VOID * pUserData;

pointer to more parameters for the callback

Sets the device event callback.

Parameter

Description

hSession

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

pfnCallBack

Pointer to a callback function. The callback function must adhere to the function syntax specified in LTWAINDEVICEEVENTCALLBACK Function.

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_TwainSetDeviceEventCallback.)

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

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

This function should be called after calling L_TwainStartCapsNeg function and before calling L_TwainEndCapsNeg function.

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.

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