LWIAENUMFORMATSCALLBACK

Summary

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.

Syntax

#include "ltwia.h"

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

Parameters

HWIASESSION hSession

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

L_INT nFormatsCount

The count of the enumerated WIA device formats.

L_INT nTransferMode

The transfer mode for the received enumerated format.

GUID * pFormat

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

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_WiaEnumFormats.)

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.
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

See Also

Functions

Topics

Example

For an example, refer to L_WiaEnumFormats.

Help Version 23.0.2024.2.29
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2024 LEAD Technologies, Inc. All Rights Reserved.

LEADTOOLS WIA C API Help
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.