CallbackFilter

Instant control over file and folder operations in Windows and .NET applications

OnPostOpenFileC event/delegate/callback

Filter:

Pascal    C++ (Lib)    C++ (VCL)    C++ (.NET)    C#    VB.NET   

CallbackFilter     See also    

Overview

This callback is called after the file/directory has been opened.

Declaration

[Pascal]
    property OnPostOpenFileC : TCbFltPostOpenFileEventC;
    TCbFltPostOpenFileEventC = procedure(Sender : TObject; FileName: TCBString; DesiredAccess: DWORD; FileAttributes: DWORD; ShareMode: WORD; Options: DWORD; CreateDisposition: WORD; Status : DWORD; var UserContext: pointer) of object;
    type TCBString = {$ifdef UNICODE}UnicodeString{$else}WideString{$endif};

[C++ (Lib)]
    typedef void (*CbFltPostOpenFileEventC)(CallbackFilter* Sender, LPWSTR FileName, DWORD DesiredAccess, DWORD FileAttributes, WORD ShareMode, DWORD Options, WORD CreateDisposition, LONG Status, PVOID* UserContext);

[C++ (VCL)]
    typedef void __fastcall (__closure *TCbFltPostOpenFileEventC)(System::TObject* Sender, TCBString FileName, unsigned long DesiredAccess, unsigned long FileAttributes, unsigned short ShareMode, unsigned long Options, unsigned short CreateDisposition, DWORD Status, void * UserContext);

[C++ (.NET)]
    public delegate void CbFltPostOpenFileEventC(CallbackFilter^ Sender, String^ FileName, UInt32 DesiredAccess, UInt32 FileAttributes, UInt16 ShareMode, UInt32 Options, UInt16 CreateDisposition, Int32 Status, IntPtr% UserContext);

[C#]
    delegate void CbFltPostOpenFileEventC(CallbackFilter Sender, string FileName, UInt32 DesiredAccess, UInt32 FileAttributes, UInt16 ShareMode, UInt32 Options, UInt16 CreateDisposition, Int32 Status, ref IntPtr UserContext);

[VB.NET]
    Delegate Sub CbFltPostOpenFileEventC(ByVal Sender As CallbackFilter, ByVal FileName As String, ByVal DesiredAccess As UInt32, ByVal FileAttributes As UInt32, ByVal ShareMode As UInt16, ByVal Options As UInt32, ByVal CreateDisposition As UInt16, ByVal Status As Int32, ByRef UserContext As IntPtr)

Parameters

  • Sender - reference to the class that called the delegate/event handler
  • FileName - contains the name of the opened file
  • DesiredAccess - requested mode of access to the opened file (dwDesiredAccess parameter of CreateFile() Windows API function)
  • FileAttributes - contains the attributes of the opened file
  • ShareMode - requested share mode (dwShareMode parameter of CreateFile() Windows API function)
  • Options - requested FILE_FLAG_xxx options (dwFlagsAndAttributes parameter of CreateFile() Windows API function)
  • CreateDisposition - requested creation disposition (dwCreationDisposition parameter of CreateFile() Windows API function)
  • Status - status code of the completed operation
  • UserContext - the placeholder for the application-defined data

Description

This callback is called after the OS has opened a file or directory with given name and attributes.
To check, what has been opened (file or directory), check FileAttributes as follows (C++ / C# notation): Directory = FileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY;

DesiredAccess, FileAttributes, ShareMode, Options and CreateDisposition are passed as they were specified in the call to CreateFile() Windows API function. For more details check MSDN library shipped with your development tool and also available online.

If your application initiates file create/open operation AND filters such requests at the same time (eg. for debugging or testing purposes), you need to set OwnProcessFiltered property to true.

The application can use UserContext to store the reference to some information, identifying the file or directory (such as file/directory handle or database record ID or reference to the stream class etc). The value, set in the event handler, is later passed to all operations, related to this file, together with file/directory name and attributes. Read more about contexts.

Read more about when excatly On*CreateFile* and On*OpenFile* callbacks are called.

See also

OwnProcessFiltered     OnOpenFileC    

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