.olb and .tlb - COM Discussion Boards

Jörgen Sigvardsson9-Jan-07 4:27

9-Jan-07 4:27

When it comes to DCOM, there should be no problems, as all communication is made over the wire. When it comes to COM - the binary standard, it will probably not work out of the box. Last time I checked, g++ did not generate ABI-compatible vtables compatible with the VC++ compiler. Some hackery in C + Wine might do the trick, but it's nothing I would like to maintain...

If you can manage to recompile components for Linux, then there is no real problem as far as binary compatibility goes.

EntireX is a system I played with a long time ago, and from what I can tell, it's still around - although unsupported! There might be other solutions too. I know there are other products for other Unix-operating systems (if I recall correctly, Microsoft bought it from Mainsoft (I think their name was) when they ported IE to Solaris).

I am however a bit skeptical about using COM-technology with Linux. It's akin to pushing a cube through a round hole - it just doesn't fit very well. Are there any specific reasons why you won't make the COM-objects to act like proxies on the Windows-side? It would be an easy task to hook it all up with RPC between Linux and Windows through the proxies. That way you can have proxy objects for communication with Linux servers, and "regular" objects for communication with Windows servers.

Is transparency is an absolute and unalterable requirement? Also, is there a design that you have to adher to, or do you have free reign on the design?

--
Verletzen zerfetzen zersetzen zerstören
Doch es darf nicht mir gehören
Ich muss zerstören

Re: COM on Linux?

Josh Smith9-Jan-07 7:45

Josh Smith

9-Jan-07 7:45

First of all, thanks a lot for the help. I really appreciate it!

Joergen Sigvardsson wrote:
I am however a bit skeptical about using COM-technology with Linux.

Me too!

Joergen Sigvardsson wrote:
Is transparency is an absolute and unalterable requirement? Also, is there a design that you have to adher to, or do you have free reign on the design?

This is a "top down" design approach, where high-level executives push down their decisions on low-level technical details. I'm just looking for ammo to shoot back with. Smile | :)

:josh:
My WPF Blog[^]

We are what we repeatedly do. Excellence then, is not an act, but a habit. - Aristotle

Re: COM on Linux?

Stephen Hewitt8-Jan-07 11:46

Stephen Hewitt

8-Jan-07 11:46

See here[^].

Steve

Re: COM on Linux?

Josh Smith8-Jan-07 11:59

Josh Smith

8-Jan-07 11:59

Thanks for the feedback.

:josh:
My WPF Blog[^]

We are what we repeatedly do. Excellence then, is not an act, but a habit. - Aristotle

how can I embed a frame on an html page Using Com

georgekjolly7-Jan-07 20:30

georgekjolly

7-Jan-07 20:30

Hi all,

I am doing a project using COM. I need to embedd my own html page as a frame in a page accessed from internet.

For Eg: I am accessing google.com , and with the help of my COM ,I should be able to embedd my own html page as a frame on the google page .

Is it Possible ??.

Thanks
George

Re: how can I embed a frame on an html page Using Com

Monty²7-Jan-07 21:03

Monty²

7-Jan-07 21:03

georgekjolly wrote:
am doing a project using COM. I need to embedd my own html page as a frame in a page accessed from internet.

Thats probably the weirdest thing i heard, why would you want to do this?

If you think you can than you can, if you think you can't you are right.

Activex Properties

Don Fletcher7-Jan-07 13:01

Don Fletcher

7-Jan-07 13:01

Hi,

I've used the MFC class wizards in VC2003 to create a wrapper for an ActiveX control (derived from CWnd). I've then successfully embedded that control into a window and it works beautifully (so far so good).

My question is, how can I invoke the control's standard Property dialog from within MFC? I need to give the user access to the control's properties at runtime, but so far have not had any luck doing this.

Can anybody help?

- Don

.olb and .tlb

HakunaMatada6-Jan-07 0:32

HakunaMatada

6-Jan-07 0:32

What is the difference between these two?

Can anyone help?

---

Hakuna-Matada Beer | [beer]

It means no worries for the rest of your days...
It's our problem free, Philosophy
Jig | [Dance]

"I think my response was 'What idiot dreamed this up?'" -- Mary Ann Davidson, Oracle's chief security officer, in typical blunt manner, remembering her reaction to the company's scheme to brand its databases as "unbreakable."

Re: .olb and .tlb

Rory Solley10-Jan-07 22:57

Rory Solley

10-Jan-07 22:57

None, aside from the naming convention.

Event Calendar

unwind_now5-Jan-07 4:06

unwind_now

5-Jan-07 4:06

I'm trying to modify a Event Calendar available here as a demo to use a sql database but have not been successful.
If anyone thinks they can help, or have something I can work with I would appreciate it.

Thanks in advance...

Compile error says: "file not found: ..\lib\ScriptHost.tlb"

nsurendran4-Jan-07 19:36

nsurendran

4-Jan-07 19:36

Hai,
I am trying to compile my application in VC++, I am getting error "file not found: ..\lib\ScriptHost.tlb". That file is not available in my machine. how to get that file? That file is included in the file

"..\Rogue Wave\Stingray Studio 2006\Include\toolkit\ActvHost\ScriptHost.rc"

Can anyone suggest me what I could do for this

Thanks

Surendran

Re: Compile error says: "file not found: ..\lib\ScriptHost.tlb"

User 2155975-Jan-07 0:26

User 215597

5-Jan-07 0:26

I haven't worked with the tookit you have mentioned so can't give specific answer about missing file. Ideally, since its a dev toolkit, the TLB, if used, should be part of the SDK/Toolkit you have installed.

If it's not, you can use following methods to generate it -
1. If you have its IDL, then use MIDL compiler to generate a TLB
2. If you have its COM component registered on system and assuming it has the TLB embeded in it, you can use OLE/COM object viewer to get the IDL file code and use step 1 to generate it

There might be other ways to generate it, but I need to fix few things myself, so can't think much at the moment Big Grin | :-D

Hope this helps.

S o h a i l K a d i w a l a

To Err Is Human; to Debug, Divine

modified 21-Apr-21 21:01pm.

Re: Compile error says: "file not found: ..\lib\ScriptHost.tlb"

Garth J Lancaster7-Jan-07 15:46

Garth J Lancaster

7-Jan-07 15:46

I would have thought that if you've paid for a RogueWave toolkit then you're entitled to a certain amount of support from RogueWave ?

'g'

Give me a simple MS COM object which raises events

JoeRip4-Jan-07 17:23

JoeRip

4-Jan-07 17:23

I have a bug in .NET which I'm trying to repro for Microsoft. To repro this bug, my app needs to respond to events raised by a COM object.

In my app, this object is iTunes. However, for my repro, I want to use a COM object already installed on a common XP setup.

So - are you aware of a COM object I can create in my app, which raises events for which I can create a handler?

Preferably, this COM object has a UI (in fact, is an application), so I can control when the events are fired. For instance, with iTunes I create an instance of iTunes, then create a handler for the VolumeChanged event, then I click on iTunes and move the volume slider. Each change sends an event to my app.

Also preferably - very little code. I can do the above with iTunes in three lines of code. I'm not interested in learning about another COM object, just using it to demo a bug. So if you can provide those 3 lines of code, more power to you! (and me).

Thanks!

Re: Give me a simple MS COM object which raises events

User 2155975-Jan-07 0:20

User 215597

5-Jan-07 0:20

How about WebBrowser control for instantiating IE. (see IWebBrowser2 interface and its related events)

S o h a i l K a d i w a l a

To Err Is Human; to Debug, Divine

modified 21-Apr-21 21:01pm.

Re: Give me a simple MS COM object which raises events

JoeRip5-Jan-07 0:45

JoeRip

5-Jan-07 0:45

That would have worked nicely, thanks.

However, I was able to fix my bug (you can see the thread over on C# if you are interested). Turns out that my event handlers for the COM object were not executing on the same thread as my form, and I was getting odd UI behavior as a result.

I needed to check .InvokeRequired, and call Invoke() if necessary. I fixed this, and every last little bit of the bug just disappeared!

I still don't know why .NET wasn't throwing "wrong thread" exceptions, but that was definitely the problem.

You can see the thread and a very nice explanation of the problem here:

http://www.codeproject.com/script/comments/forums.asp?forumid=1649&fr=26

Re: Give me a simple MS COM object which raises events

User 2155975-Jan-07 3:36

User 215597

5-Jan-07 3:36

Cool. I agree, there are problems with events when multiple threads are involved. Need to be a bit careful Smile | :)

I was unable to get to the thread using the link you provided Frown | :(

S o h a i l K a d i w a l a

To Err Is Human; to Debug, Divine

modified 21-Apr-21 21:01pm.

Re: Give me a simple MS COM object which raises events

Mike Dimmick5-Jan-07 5:23

Mike Dimmick

5-Jan-07 5:23

JoeRip wrote:
Turns out that my event handlers for the COM object were not executing on the same thread as my form, and I was getting odd UI behavior as a result.

Awooga! Awooga!

Sorry, that's the sound of the alarm going off in my head.

Something's not right with your apartment setup. If you have forms, the thread that creates them should be marked with the [STAThread] attribute. This ensures that COM events are fired on the correct thread - it tells COM that this thread uses the apartment-threaded model (CoInitializeEx is called with the COINIT_APARTMENTTHREADED flag). Objects created by this thread have their calls sent back to this thread, regardless of which thread those calls were made from (if the object is implemented correctly).

The object is also marked for a given threading model - this is done in the registry for objects implemented as in-process servers (in DLLs). Normally automation objects are also marked apartment-threaded - this means that whichever thread you make a call to them on, COM will marshal the call to the thread you created the object on. However, COM can only do its stuff if you correctly marshal interface pointers between threads - if you just pass raw interface pointers around you can end up calling an object incorrectly on the wrong thread when it's not expecting it, causing unexpected race conditions or other thread-model violations. This is a particular problem if an event has to be raised by a worker thread.

This shouldn't happen if you're using an out-of-process object though, since those calls always need to be marshalled, which leads me to think that your UI thread isn't marked [STAThread].

Stability. What an interesting concept. -- Chris Maunder

Re: Give me a simple MS COM object which raises events

JoeRip5-Jan-07 11:03

JoeRip

5-Jan-07 11:03

Ah, but it is. I'm using the standard VS .NET Windows Application template. Here's my main:

namespace Eye_On_iTunes<br />
{<br />
    static class Program<br />
    {<br />
        /// <summary><br />
        /// The main entry point for the application.<br />
        /// </summary><br />
        [STAThread]<br />
        static void Main()<br />
        {<br />
            Application.EnableVisualStyles();<br />
            Application.SetCompatibleTextRenderingDefault(false);<br />
            Application.Run(new frmEye_On_iTunes());<br />
        }<br />
    }<br />
}

and all of my code is running in the form class frmEye_On_itunes(). Note the thread model.

To get the iTunesApp object, I simply:

itunesapp = new iTunesLib.iTunesApp();

and to create event handlers for the iTunes events I simply

itunesapp.OnDatabaseChangedEvent += new _IiTunesEvents_OnDatabaseChangedEventEventHandler(itunes_OnDatabaseChangedEvent);

where itunes_OnDatabaseChangedEvent is a handler in the form class.

So I also assumed the event handler thread would be the form thread, and that it would be safe. However, apparently it wasn't.

I added a check to InvokeRequired, and re-routed the message back through with a delegate, like this:

private void itunes_OnDatabaseChangedEvent(object deletedObjectIDs, object changedObjectIDs)<br />
  {<br />
    if (InvokeRequired)<br />
      {<br />
        Invoke(new iTunesLib._IiTunesEvents_OnDatabaseChangedEventEventHandler(itunes_OnDatabaseChangedEvent), new object[] { deletedObjectIDs , changedObjectIDs});<br />
      }<br />
      else<br />
      {<br />
        // update UI<br />
      }<br />
  }

and all problems went away. So .NET says that InvokeRequired is true when this event fires for the COM object itunesapp, apparently.

Sinking HTMLWindowEvents2::OnUnload

A_L4-Jan-07 15:34

A_L

4-Jan-07 15:34

Hi,
I am trying to hook into this HTMLWindow event.
Here is what I am doing :
In MyHandler class :

COM_INTERFACE_ENTRY_IID(DIID_HTMLWindowEvents2, IDispatch)

virtual HRESULT __stdcall onunload(IHTMLEventObj* pEvtObj) { ... }

STDMETHODIMP DocumentComplete(IDispatch *disp,
VARIANT *url) {
....
HRESULT hr = S_OK;
LPDISPATCH doc_disp = NULL;
CComQIPtr<ihtmldocument2> doc;
hr = browser->get_Document(&doc_disp);
doc = doc_disp;
....
SomeOtherFunc1(doc);
}

void SomeOtherFunc1(IHTMLDocument2* doc) {
CComQIPtr<ihtmlwindow2> wnd;
hr = doc->get_parentWindow(&wnd);
SomeOtherFunc 2(wnd);
}

void SomeOtherFunc 2(IHTMLWindow2* wnd) {
AtlAdvise( wnd, (IDispatch*)this,
DIID_HTMLWindowEvents2, &cookie);
}

The handler class is already hooking into DWebBrowserEvents2 and all the handlers get called (DocumentComplete among them).
And I added similar code for the HTMLWindowEvents2.
AtlAdvise returns S_OK and inside it finds the CPC and the CP and Advise returns success and a valid cookie.
But onunload is not called when I navigate away from a page.
The module is a BHO dll loaded by IE.

I believe the HTMLWindowEvents2 interface is dual so I should be able to use VTBL events, right ?
Am I missing something here ?

--
Thank you!

matlab help ??? please

ersincakir4-Jan-07 15:24

ersincakir

4-Jan-07 15:24

i made a program with matlab gui(guide user interface).
it works so right. i have two file first with *.fig extention
second with *.m extention

my problem is how to make my program a standlone application (with *.exe extention)..
how to convert fig file to exe file in matlab??

thanks..

uLTraSLan-uNi

C# and COM - exporting enum-s

Vitaly Tomilov4-Jan-07 0:42

Vitaly Tomilov

4-Jan-07 0:42

Hi,

I'm writing a COM interop interface in C# (VS2005) to be used in VC++, and got into problem of proper exporting enum-s in such interface.

When i previously used C++ for writing COM interfaces, i would just declare the enum within IDL file, and then within the library section also declare it, that way way making my enum accessible when TLB file is imported using #import in C++;

Now in C# if i declare: public enum MyEnymType {val1, val2,...}, then such object when imported into C++ project is declared as: enum MyEnymType {MyEnymType_val1, MyEnymType_val2,...} instead of enum MyEnymType {val1, val2,...}

Is there a way to make C# embed my enum type into the object in such a way that it exports original enum declaration during import instead of such an ugly Type_Value thing?

Thank you,
Vitaly

Free C++ libraries with source code on www.neatcpp.com: TWAIN, DirectShow, Interprocess Communications, etc...

Re: C# and COM - exporting enum-s

Pete O'Hanlon4-Jan-07 2:53

Pete O'Hanlon

4-Jan-07 2:53

Please don't cross post.

the last thing I want to see is some pasty-faced geek with skin so pale that it's almost translucent trying to bump parts with a partner - John Simmons / outlaw programmer

Deja View - the feeling that you've seen this post before.

Re: C# and COM - exporting enum-s

Vitaly Tomilov4-Jan-07 3:11

Vitaly Tomilov

4-Jan-07 3:11

My question is on C# and COM at the same time - which is the right place to post then, if not in both C# and COM forums?....

Free C++ libraries with source code on www.neatcpp.com: TWAIN, DirectShow, Interprocess Communications, etc...

Re: C# and COM - exporting enum-s

Pete O'Hanlon5-Jan-07 3:30

Pete O'Hanlon

5-Jan-07 3:30

It is normal to post them on one forum. Pick the one that you think is most appropriate and then post it there. In this case, it is more relevant to the C# forum because that is where you want to override the enum.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.