L_TwainQueryFileSystem

#include "lttwn.h"

L_LTTWN_API L_INT L_TwainQueryFileSystem(hSession, FileMsg, pTwFile)

HTWAINSESSION hSession;	/* handle to an existing TWAIN session */
FILESYSTEMMSG FileMsg;	/* file system message */
pTW_FILESYSTEM pTwFile;	/* pointer to a structure */

Performs certain tasks, or retrieves certain information, depending on the value of the FileMsg parameter.

Parameter	Description
hSession	Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession function.
FileMsg	Files system messages that determine the behavior of the function. For possible values, refer to the FILESYSTEMMSG.
pTwFile	Pointer to a TW_FILESYSTEM structure. This structure will be updated with, or will contain information used to change, the current TWAIN file system settings. This structure must be allocated.

Returns

SUCCESS	The function was successful.
! = SUCCESS	An error occurred. Refer to Return Codes.

Comments

This function is only valid for TWAIN file systems for digital camers.

This function must be called after calling the L_TwainStartCapsNeg function and before calling the L_TwainEndCapsNeg function.

If the FileMsg parameter contains one of the following flags:

FILESYSTEMMSG_CHANGEDIRECTORY

FILESYSTEMMSG_CREATEDIRECTORY

FILESYSTEMMSG_DELETE

FILESYSTEMMSG_FORMATMEDIA

FILESYSTEMMSG_RENAME

FILESYSTEMMSG_COPY

the pTwFile parameter must contain the proper information before calling this function. This function will use the provided information to changes settings within the TWAIN files system.

If the FileMsg parameter contains one of the following flags:

FILESYSTEMMSG_GETCLOSE

FILESYSTEMMSG_GETFIRSTFILE

FILESYSTEMMSG_GETINFO

FILESYSTEMMSG_GETNEXTFILE

this function, will update the pTwFile parameter with the corresponding information.

If the FileMsg parameter contains the following flag:

FILESYSTEMMSG_AUTOMATICCAPTUREDIRECTORY

this function will use information stored within the pTwFile parameter and will update the pTwFile parameter with any appropriate information.

For more information on the TW_FILESYSTEM structure, please refer to the TWAIN 1.9 Specification, available at www.twain.org.

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_TwainInitSession, L_TwainEndSession, L_TwainStartCapsNeg, L_TwainEndCapsNeg
Topics:	Getting or Setting TWAIN File System Information
	TWAIN Functionality: Twain File System Functions

Example

 L_INT TwainQueryFileSystemExample(HWND hWnd)
{
   HTWAINSESSION hSession;
   APPLICATIONDATA AppData;
   TW_FILESYSTEM twFileSys;
   AppData.hWnd = hWnd;
   lstrcpy (AppData.szManufacturerName, TEXT("LEAD Technologies, Inc."));
   lstrcpy (AppData.szAppProductFamily, TEXT("LEAD Sample"));
   lstrcpy (AppData.szVersionInfo, TEXT("Version 1.0"));
   lstrcpy (AppData.szAppName, TEXT("LEAD Sample"));
   AppData.uStructSize = sizeof(APPLICATIONDATA);
   L_INT nRet = L_TwainInitSession(&hSession, &AppData);
   if (nRet != TWAIN_SUCCESS)
   {
      MessageBox(hWnd, TEXT("Error occurred during L_TwainInitSession"), TEXT("Notice"), MB_OK);
      return nRet;
   }
 
   nRet = L_TwainStartCapsNeg(hSession);
   if(nRet != SUCCESS)
      return nRet;
   memset(&twFileSys, 0, sizeof(TW_FILESYSTEM));
   nRet = L_TwainQueryFileSystem(hSession, FILESYSTEMMSG_AUTOMATICCAPTUREDIRECTORY, &twFileSys);
   if (nRet != TWAIN_SUCCESS) 
   {
      MessageBox(hWnd, TEXT("Error occurred during L_TwainQueryFileSystem"), TEXT("Notice"), MB_OK);
      return nRet;
   }
   
   nRet = L_TwainEndCapsNeg(hSession);
   if(nRet != SUCCESS)
      return nRet;
   nRet = L_TwainEndSession(&hSession);
   if(nRet != SUCCESS)
      return nRet;
   
   return SUCCESS;
}