OnFileCreate event/delegate/callback


Pascal    Plain C    C++ (DLL/Lib)    C++ (VCL)    C++ (.NET)    C#    VB.NET    Java 

SolFSStorage     See also    


This event is fired when storage needs to be created.


    TSolFSCreateFileEvent = procedure( Sender : TObject; const FileName : TSolFSString; var FileHandle : THandle; Overwrite : boolean; IsJournalFile : boolean; var Result : LongInt) of object;

[Plain C]
    typedef Error (__stdcall *SolFSCreateFileFunc)( LongWord UserData, PWideChar FileName, PHandle FileHandle, Bool Overwrite, Bool IsJournalFile);

[C++ (DLL/Lib)]
    typedef Error (__stdcall *SolFSCreateFileFunc)( LongWord UserData, PWideChar FileName, PHandle FileHandle, Bool Overwrite, Bool IsJournalFile);

[C++ (VCL)]
    typedef void (__closure *TSolFSCreateFileEvent)( System::TObject* Sender, PWideChar FileName, PHandle FileHandle, Bool Overwrite, Bool IsJournalFile, Error& Result);

[C++ (.NET)]
    public __delegate void SolFSCreateFileEvent( SolFSStorage* Sender, System::String* FileName, UInt32 __gc &FileHandle, bool Overwrite, bool IsJournalFile, Int32 __gc &Result);

    public void SolFSCreateFileEvent( SolFSStorage Sender, string FileName, ref uint FileHandle, bool Overwrite, bool IsJournalFile, ref int Result);

    Sub SolFSCreateFileEvent( ByVal Sender As SolFSStorage, ByVal FileName As String, ByRef FileHandle As UInt32, ByVal Overwrite As Boolean, ByVal IsJournalFile As Boolean, ByRef Result As Int32)

    void ISolFSFileEvents.onFileCreate( String fileName, boolean overwrite, boolean isJournalFile)


  • Sender - reference to the class that called the delegate/event handler.
  • FileName - the name of the storage as passed to SolFSStorage.Create constructor.
  • FileHandle - the place where the event handler must place some handle, that uniquely identifies the storage object. This handle is later passed to other events. Set this parameter to -1 ($FFFFFFFF, 0xFFFFFFFF) if the file could not be opened.
  • Overwrite - specifies if the storage, if it already exists, may be overwritten.
  • IsJournalFile - This parameter is always false.
  • Result - out parameter (return value for DLL) where the application places the result of the operation. If you are working with file system, Win32 error code is a good candidate for placing to Result parameter. Otherwise you can use any other error codes, just be sure that 0 means success.
    [Java]See Description for details about error reporting in Java.

  • [Plain C] UserData - application-defined parameter which is specified when creating the storage and passed back to callback function.


The event is fired when new storage is to be created. The application must create the storage and return some handle to this storage. The handle will be passed to other delegate/event handlers for further file manipulation.

The callback/event handler must be set before the storage is opened.

You need to implement ISolFSFileEvents interface in your code and pass the object, that implements the events, to one of SolFSStorage constructors that accept storageEvents parameter.

ERROR REPORTING: In Java you can't return more than one parameter, so the natural way is to throw an exception. You can throw any exception, and this exception will be passed back to the code, which called one of CBFS Storage functions. So if you use callback mechanism and throw exception from within event handlers, be sure to wrap each call to CBFS Storage methods with try/catch.

See also

Information about callbacks (Operating System edition only)     OnFileClose     OnFileOpen