Help Version 19.0.2017.10.27
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#include "ltwia.h"
L_INT pEXT_CALLBACK YourFunction(hSession, pszFilename, uPercent, uFlags, pUserData)
HWIASESSION hSession; |
handle to an existing WIA session |
L_TCHAR * pszFilename; |
file name |
L_UINT32 uPercent; |
the percent completion of the acquire process |
L_UINT32 uFlags; |
flags that indicates whether the device finished acquiring the page |
L_VOID * pUserData; |
pointer to additional parameters |
Called for each image being acquired from the WIA source to the application. The address of this callback is passed as an argument in L_WiaAcquireToFile.
| Parameter | Description | |
| hSession | Handle to an existing WIA session. This handle is obtained by calling the L_WiaInitSession function. | |
| pszFilename | Character string containing the name of the file to which to save the scanned image(s). | |
| uPercent | The percent completion of the page being scanned. | |
| uFlags | Flag that indicates the start or the end of the scanned page. Possible values are: | |
| Value | Meaning | |
| 0 | Default value when this is not the first transferred chunk or the last transferred chunk. | |
| L_WIA_ACQUIRE_START_OF_PAGE | [0x00000001] Indicates the start of the page being scanned. | |
| L_WIA_ACQUIRE_END_OF_PAGE | [0x00000002] Indicates the end of the page being scanned. Use this value to reset the progress bar. | |
| 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_WiaAcquire or L_WiaAcquireSimple.) | |
| Keep in mind that this is a void pointer, which must be cast to the appropriate data type within your callback function. | ||
SUCCESS |
The function was successful. |
ERROR_USER_ABORT |
The callback wants to abort the scanning operation. |
< 1 |
An error occurred. Refer to Return Codes. |
This feature is available in version 16 or higher.
Called many times to provide the user with a status update of the acquire progress, in percent. It is also called when the page ends to pass you the L_WIA_ACQUIRE_END_OF_PAGE flag in the uFlags parameter.
Note: |
If you are using WIA 2.0 while the L_WIA_SHOW_USER_INTERFACE is set then no need to provide a callback pointer since Microsofts WIA 2.0 acquire dialog doesnt provide a callback and it does all the process and return back to you with the saved files count and paths. |
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. |