#include "lttwn.h"
L_LTTWN_API L_INT L_TwainGetSources (hSession, pfnCallBack, uStructSize, uFlags, pUserData)
HTWAINSESSION hSession; |
handle to an existing TWAIN session |
LTWAINSOURCEINFOCALLBACK pfnCallBack; |
optional callback function |
L_UINT uStructSize; |
size in bytes, of the structure passed to the callback function |
L_UINT uFlags; |
optional flags |
L_VOID * pUserData; |
pointer to more parameters for the callback |
Gets the available information for the TWAIN sources installed on the system.
Parameter | Description | |
hSession | Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession or L_TwainInitSession2 function. | |
pfnCallBack | Callback function for processing each enumerated TWAIN source. Use the function pointer as the value of this parameter. | |
L_TwainGetSources calls this callback function as it gets each TWAIN source. The callback function must adhere to the function prototype described in LTWAINSOURCEINFOCALLBACK Function. | ||
uStructSize | Size in bytes, of the structure passed to the LTWAINSOURCEINFOCALLBACK callback function, for versioning. Use sizeof(LTWAINSOURCEINFO). | |
uFlags | Flags that indicate what sources to get. Possible values are: | |
Value | Meaning | |
LTWAIN_SOURCE_ENUMERATE_ALL | [0x0000] Enumerates all the available sources. | |
LTWAIN_SOURCE_ENUMERATE_DEFAULT | [0x0001] Gets only the default source (currently selected). | |
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. |
sdsf
Required DLLs and Libraries
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_TwainSelectSource, L_TwainInitSession, L_TwainInitSession2 |
Topics: |
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Programming with LEADTOOLS TWAIN Functions |
L_INT EXT_CALLBACK TwnSourcesCB(HTWAINSESSION hSession,
pLTWAINSOURCEINFO pSource,
L_VOID * pUserData)
{
UNREFERENCED_PARAMETER(hSession);
UNREFERENCED_PARAMETER(pUserData);
L_TCHAR szBuffer[MAX_PATH];
memset(szBuffer, 0, sizeof(szBuffer));
wsprintf(szBuffer, TEXT("Source Name = %s\nSource Version = %s\nProduct Family = %s\nManufacturer = %s\n"),
pSource->pszTwnSourceName,
(pSource->TwainVersion == TWAIN_VERSION1) ? TEXT("1.0") : TEXT("2.0"),
pSource->pszTwnProductFamily,
pSource->pszTwnManufacturer);
MessageBox(NULL, szBuffer, TEXT("Source Info."), MB_OK);
return TWAIN_SUCCESS;
}
L_INT TwainGetSourcesExample(HTWAINSESSION hSession)
{
L_INT nRet;
nRet = L_TwainGetSources(hSession,
TwnSourcesCB,
sizeof(LTWAINSOURCEINFO),
LTWAIN_SOURCE_ENUMERATE_ALL,
NULL);
if (nRet != SUCCESS)
{
MessageBox (NULL, TEXT("Error During Enumeration Procedure"), TEXT("ERROR"), MB_OK);
return nRet;
}
return SUCCESS;
}