L_TwainGetSources

#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.

Returns

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.

See Also

Functions:

L_TwainSelectSourceL_TwainInitSessionL_TwainInitSession2

Topics:

Managing the TWAIN Source

 

TWAIN Functionality: Property Functions

Programming with LEADTOOLS TWAIN Functions

Example

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_LTTWNTEX_API  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; 
} 

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