LWIAENUMFORMATSCALLBACK

#include "ltwia.h"

L_INT pEXT_CALLBACK YourFunction(hSession, nFormatsCount, nTransferMode, pFormat, pUserData)

HWIASESSION hSession;

handle to an existing WIA session

L_INT nFormatsCount;

enumerated formats count

L_INT nTransferMode;

transfer mode for the enumerated format

GUID * pFormat;

pointer to GUID structure that contains the enumerated format

L_VOID * pUserData;

pointer to additional parameters

Called for each enumerated capability of the WIA device and also lets the user abort the enumeration process. The address of this callback is passed as an argument in L_WiaEnumCapabilities function.

Parameter

Description

hSession

Handle to an existing WIA session. This handle is obtained by calling the L_WiaInitSession function.

nFormatsCount

The count of the enumerated WIA device formats.

nTransferMode

The transfer mode for the received enumerated format.

pFormat

Pointer to a GUID structure that contains the received enumerated format.

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_WiaEnumFormats.)

 

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.

ERROR_USER_ABORT

The callback wants to abort the properties set process.

< 1

An error occurred. Refer to Return Codes.

Comments

This feature is available in version 16 or higher.

Call this function to provide the user with information about the available transfer format of the selected WIA device and also to allow the user to abort the enumeration process.

Required DLLs and Libraries

LTWIA

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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