HTWAINSESSION hSession;

/* handle to an existing TWAIN session */

pLTWAINPROPERTIES pltProperties;

/* pointer to a structure */

L_UINT uFlags;

/* optional flags */

LTWAINSETPROPERTYCALLBACK pfnCallBack;

/* optional callback function */

L_VOID * pUserData;

/* pointer to more parameters for the callback */

Parameter

Description

hSession

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

pltProperties

Pointer to a LTWAINPROPERTIES structure that contains the values to set.

uFlags

Flags that indicate whether to set or reset the property values. Possible values are:

Value

Meaning

LTWAIN_PROPERTIES_SET

[1] Set the properties to the values specified in the LTWAINPROPERTIES structure.

LTWAIN_PROPERTIES_RESET

[2] Set the properties to their default values neglecting the values specified in the LTWAINPROPERTIES structure. In this case the LTWAINPROPERTIES pointer can be NULL since it is not used.

pfnCallBack

Optional callback function, called as each property is set. It lets the user know if an error occurred during the set operation and lets the user abort or retry.

If you do not provide a callback function, use NULL as the value of this parameter. No error reporting will occur.

If you do provide a callback function, use the function pointer as the value of this parameter.

The callback function must adhere to the function prototype described in LTWAINSETPROPERTYCALLBACK function.

pUserData

Void pointer that you can use to pass one or more additional parameters that the callback function needs.

To use this feature, assign a value to a variable or create a structure that contains as many fields as you need. Then, in this parameter, pass the address of the variable or structure, casting it to L_VOID *. The callback function, which receives the address in its own pUserData parameter, can cast it to a pointer of the appropriate data type to access your variable or structure.

If the additional parameters are not needed, you can pass NULL in this parameter.

SUCCESS

The function was successful.

! = SUCCESS

An error occurred. Refer to Return Codes.

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_TwainEndCapsNeg, L_TwainGetProperties, L_TwainSetCapability, L_TwainGetCapability, L_TwainInitSession, L_TwainEndSession.

Topics:

Getting and Setting Capabilities

TWAIN Functionality: Property Functions.