How to handle OLE objects in database

Question

5.00/5 (2 votes)

See more:

Hello,
I do have a MSSQL table in which a column contains numerous OLE objects.
Contents are various types and versions of MS Office documents + TIF Images (Typical office stuff).
Case: Need of an application that can handle those documents (if required applications are installed) and some other tasks.
My thoughts:
1- Pop objects - rip ole struct according to Windows Compound Binary File Format Specification[^] - push back raw files - add a type field to the table - perform other tasks.
But automation hell arises.
2- Make a .dll in an older IDE which has OleConteiner - somehow pass OLE to dll - take it back if and when done - perform other tasks.
But... I don't really know how many things can go wrong.

The question is, what should I do? Is there a feasible way to handle OLE objects?

Progress Update:
1- Rip ole:

C#

public void ReadnDump(System.IO.Stream p_Stream,string p_FileName)
{
    System.IO.BinaryReader br = new System.IO.BinaryReader(p_Stream);
    m_head = new Header();
    m_DirEntities = new System.Collections.Generic.List<DirectoryEntry>();
    m_FAT = new System.Collections.Generic.List<UInt32>();
    m_DiFAT = new System.Collections.Generic.List<UInt32>();
    m_MiniFAT = new System.Collections.Generic.List<UInt32>();
    m_MiniStream = new System.IO.MemoryStream();
    m_DirDictonary = new System.Collections.Generic.Dictionary<string,DirectoryEntry>();
    byte[] buffer;
    // Binary reading stuff below explained in link above
    readHeader(ref br);
    readFAT(ref br);
    readDirectoryEntities(ref br);
    readMiniFat(ref br);
    string fileName;
    string className = readCompObjClassName();
    UInt32 sect;
    int fileSize;
    System.IO.FileStream fw;
    switch (className)
    {
        // Some cases...
        case "Word.Document.12":
        {
            sect = m_DirDictonary["\\Root Entry\\Package"]._sectStart;
            // Dump contents to file named "p_FileName" + decided extention...
            break;
        }
        // Some more cases...
    }
}

Automation... I hope it does not come to this.

2- Managed to write a Delphi dll and open ole but... Event sink, callbacks waiting for me yay!

Posted 28-Apr-11 7:18am

yesotaso

Updated 29-Apr-11 5:27am

v3

Add a Solution

Comments

Manfred Rudolf Bihy 28-Apr-11 14:02pm

Sounds like an interesting question to me. Let's see what the seasoned OLE specialists aboard CP have to say to this.

Rajesh Lagaria 28-Apr-11 20:22pm

send your code ! what you do

yesotaso 28-Apr-11 22:10pm

Function OleTest(p1:PChar): Boolean; StdCall;
var ole1:TOleContainer;
fstr:TFileStream;
Begin
OleTest:= False;
ole1 := TOleContainer.CreateParented(0);
fstr := TFileStream.Create(p1,fmRead);
ole1.LoadFromStream(fstr);
ole1.DoVerb(ovPrimary);
..... Test dll

Manfred Rudolf Bihy 29-Apr-11 8:38am

How come you replied to my comment? I do hope this was done by mistake ;)

yesotaso 29-Apr-11 11:04am

:) Mistake indeed.

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

yesotaso · Accepted Answer · 2011-05-08T04:22:00

Ok I came up with solution as:

Delphi side: Created Dll with 6 exports and a little factory inside.

Init
CleanUp
RegisterCallback
OleOpen
OleCreateFromFile
OleClose

C# side:

C#

//Delegate for dll callbacks
[UnmanagedFunctionPointer(CallingConvention.StdCall)]
public delegate void ProcDelegate(int value,int callerID);
private static ProcDelegate procDelegate;
// Declarations for exports
[DllImport("OleWrapper.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi)]
public static extern void InitOle();
// And 5 more for each exported functions

// Delegated function
// value is an arbitrary number I decided to identify operation
// callerID is the container ID which is returned by OleOpen or OleCreateFromFile
public void DelphiCallBack(int value, int callerID)
{
    int index;
    switch (value)
    {
         case 1:
             // Close
             // this creates a temporary file to be inserted to DB as it is
             OleClose(callerID);
             // tag and bag C# side of open item list
             break;
         case 2:
             // Datachanged - some debug stuff. Just ignore
             break;
         case 3:
             // Save
             // User pressed saved the open document.
             // handle created temporary file
             break;
         case 4:
             // Renamed - some debug stuff. Just ignore
             break;
         case 5:
             // View changed - some debug stuff. Just ignore
             break;
     }
}

Init and RegisterCallback called before doing anything else CleanUp destroys the factory.
Only problem is I tried to avoid memory contact with dll so that I used temporary files to pass OLE objects back and forth. Any further suggestion is welcome.