L_TwainSetDeviceEventCallback

Show in webframe

#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 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.

Functions:	L_TwainStartCapsNeg, L_TwainGetDeviceEventData, L_TwainSetDeviceEventCapability, L_TwainGetDeviceEventCapability, L_TwainResetDeviceEventCapability, LTWAINDEVICEEVENTCALLBACK
Topics:	Getting and Setting Capabilities
	TWAIN Functionality: Capability Functions