L_TwainQueryFileSystem

Summary

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

Syntax

L_LTTWN_API L_INT L_TwainQueryFileSystem(hSession, FileMsg, pTwFile)

Parameters

HTWAINSESSION hSession

Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession or L_TwainInitSession2 function.

FILESYSTEMMSG FileMsg

File system messages that determine the behavior of the function. For possible values, refer to the FILESYSTEMMSG.

If the FileMsg parameter contains one of the following flags, this function will use the provided information to change settings within the TWAIN file system:

• FILESYSTEMMSG_CHANGEDIRECTORY
• FILESYSTEMMSG_CREATEDIRECTORY
• FILESYSTEMMSG_DELETE
• FILESYSTEMMSG_FORMATMEDIA
• FILESYSTEMMSG_RENAME
• FILESYSTEMMSG_COPY

The pTwFile parameter must contain the proper information before calling this function.

If the FileMsg parameter contains one of the following flags, this function will update the pTwFile parameter with the corresponding information:

• FILESYSTEMMSG_GETCLOSE
• FILESYSTEMMSG_GETFIRSTFILE
• FILESYSTEMMSG_GETINFO
• FILESYSTEMMSG_GETNEXTFILE

If the FileMsg parameter contains the following flag, this function will use information stored within the pTwFile parameter and will update the pTwFile parameter with any appropriate information:

FILESYSTEMMSG_AUTOMATICCAPTUREDIRECTORY

pTW_FILESYSTEM 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

Comments

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

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

For more information on the TW_FILESYSTEM structure, refer to the TWAIN specification.

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; 
}