References ▼
Sets the device event callback.
#include "lttwn.h"
L_LTTWN_API L_INT L_TwainSetDeviceEventCallback(hSession, pfnCallBack, pUserData)
Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession or L_TwainInitSession2 function.
Pointer to a callback function. The callback function must adhere to the function syntax specified in LTWAINDEVICEEVENTCALLBACK Function.
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.
| Value | Meaning |
|---|---|
| SUCCESS | The function was successful. |
| < 1 | An error occurred. Refer to Return Codes. |
This function should be called after calling L_TwainStartCapsNeg function and before calling L_TwainEndCapsNeg function.
For an example, refer to L_TwainGetDeviceEventData.