Deleting mutiple instances of COM object - COM Discussion Boards

Ernest Laurentin17-Jan-02 5:26

17-Jan-02 5:26

One of the easiest way to use the BSTR type as normal string, in my opinion is
to use the compiler string type: _bstr_t
Use like this:

HRESULT Write(BSTR message)
{
 _tprintf(TEXT("Message:%s\r\n", (LPCTSTR) _bstr_t(message));
}

You can look at the description for _bstr_t in MDSN for more help.
It can also convert ASCII string to Unicode. You may want to use conversion macro.

HRESULT Write(BSTR message)
{
USES_CONVERSION;
LPCTSTR lpszNormal = OLE2CT(message);
 _tprintf(TEXT("Message:%s\r\n", (LPCTSTR) lpszNormal);
}

Re: BSTR

Not Active17-Jan-02 5:29

Not Active

17-Jan-02 5:29

CComBSTR

Re: BSTR

pba_24-Jan-02 7:17

pba_

24-Jan-02 7:17

MultiByteToWideChar / WideCharToMultiByte or mbstowcs / wcstombs Wink | ;)

Re: BSTR

yamini13-Feb-02 1:14

yamini

13-Feb-02 1:14

There are 2ways to do this
The first method uses the OLE2T() for BSTR conversion to string.

The second method uses _bstr_t for conversion.
******************************************************#inclu#include <iostream.h>
#include <atlbase.h>
#include <comdef.h>
void main()
{
BSTR b=L"StringConversion"; //BSTR string
USES_CONVERSION; //First method of Conversion
cout<<"String :"<

Events in MFC client

Member 1697717-Jan-02 1:26

Member 16977

17-Jan-02 1:26

Hi,All
I have a component(built using ATL) which supports outgoing interfaces.I want to use this component in MFC client.
When component fires an event i want to trap it and show the string which it sends in the modeless dialog box.
I dont know how to trap events in MFC client.
Can anybody help.
Regards
Tushar

Re: Events in MFC client

Prem Kumar19-Jan-02 10:58

Prem Kumar

19-Jan-02 10:58

Look at the MSDN KB article Q181845.
"HOWTO: Create a Sink Interface in MFC-Based COM Client".

regards,
Prem

Re: Events in MFC client

Matt Philmon13-Feb-02 17:51

Matt Philmon

13-Feb-02 17:51

Let me know if you get really stuck. Connection Points are just as unbelieably hard to handle in MFC applications as they are easy in VB. I can give you some details or examples if you need it.

Deleting mutiple instances of COM object

Ebin16-Jan-02 20:01

Ebin

16-Jan-02 20:01

We have implemented a com client in VC++ and it should communicate with server that developed in Delphi(.dll).

The Scenario is as folows
-------------------------------------

A button click on com client(vc) will invoke the com server (Delphi interface)(dialog based).
which will display a dialog were user can interact.Thus by the button click on VC client(dialog based) can invok multiple instances of delphi server.

Now we need to delete or close all the instances of com server with a single click in vc client (com client)
how it is possible ?.

Thanks in Advance
eby

Re: Deleting mutiple instances of COM object

Henrik Sternberg18-Jan-02 1:02

Henrik Sternberg

18-Jan-02 1:02

Hello Eby,

What kind of server is it? (IN/OUT of process)

Can you provide more details?

Regards,

/_henrik

Henrik Sternberg, Consultant
Cambridge Technolgy Partners, Germany
www.ctp.com/ce

henrik.sternberg@ctp.nospam.com
(take away nospam)

Re: Deleting mutiple instances of COM object

Prem Kumar19-Jan-02 11:03

Prem Kumar

19-Jan-02 11:03

Hi,

Since the Client invokes the server application,
u could have a the interface pointers stored in a
list and close all of them when ever u want to.

But this sounds probably too easy or may be i am not
aware of any additional details where u r facing problems
but from ur q's these should work.

regards,
Prem

GIT in Worker Thread Crashes

16-Jan-02 6:42

Hi, I'm creating a worker thread in my ATL Object, and all the events seem to be getting handled right at the end. This has happened with many other people, and there are plenty of "What to do's" but not "How to do it".

So i'm trying to use a GlobalInterfaceTable which supposedly is the easiest and i'm trying it "last" (hoping this will be the last).. i tried using CoMarshalblahblah() but it still does the same thing w/o using those functions by just passing object through the LPARAM of CreateThread().

So anyways, it crashes in OLE32.exe when i call GetInterfaceFromGlobal(). It seems to get the Cookie fine and everything, but... when that function is called... it crashes.. and i dont know what i'm doing wrong... it's really frustrating cuz i've worked on this for a LONG TIME... Dead | X|

so I think some source sample would be awesome. a few things:

********
# Where do i call CoCreateInstance() & GetInterfaceInGlobal()? From the function that creates the thread or from inside the thread? (i assumed it would be in my Function that creates the thread.

# I only have one of these objects right at the moment, so i just made the DWORD g_dwCookie "global", and I was passing the GIT through the LPARAM of CreateThread() and then calling
GetInterfaceFromGlobal(cookie, IID_ISpyder, (void**)Spy);
*for the record Spy is just a ISpyder *Spy = NULL; that's ok right?

Coolio, anyone lemme know if you can help me! Source or advise is cool! Thanks in advance!

~Timothy T. Rymer

www.digipen.edu
tim.xpertz.com

Re: GIT in Worker Thread Crashes

Joao Vaz16-Jan-02 7:44

Joao Vaz

16-Jan-02 7:44

Hi,

1- If you make the variable global why passing it in the LPARAM of createThread ?
Normally , or you make a variable global or you pass the variable thru the LPARAM.
2- Normally, with multiple threads in a process a guy must protect the data with a critical section or with another sinchronization stuff ...
3-It's necessary to call CoCreateInstance and RegisterInterfaceInGlobal on the apartment where the object lives
4- It must be GetInterfaceFromGlobal(cookie, IID_ISpyder, (void**)&Spy)), you forgot the ampersand Confused | :confused:

5-You can call RevokeInterfaceFromGlobal from any apartment, but you must be certain that is the last apartment that makes use of the interface pointer

Hope this helps, best of luck

Joao Vaz

Re: GIT in Worker Thread Crashes

Tim Rymer16-Jan-02 8:23

Tim Rymer

16-Jan-02 8:23

the only thing global is the cookie, i went ahead and made the GIT a member in my class, and passed it in through the LPARAM. but i didnt put my ampresand in there though. gonna try the stuff out now...

~Timothy T. Rymer

www.digipen.edu
tim.xpertz.com

Re: GIT in Worker Thread Crashes

Tim Rymer16-Jan-02 9:03

Tim Rymer

16-Jan-02 9:03

now when i call RegisterInterfaceInGlobal() - what should i pass in the first parameter? What do i do & How do i do it?

Do i just call QueryInterface? all i'm wanting is ISpyder but i'm in a CSpyder function... how do i do all that?

right now to get some kind of pointer, i call query interface and then pass an IUnknown *unk = NULL ---> (void**)&unk <--- into the function.

Thanks again..

~Timothy T. Rymer

www.digipen.edu
tim.xpertz.com

Re: GIT RegisterInterfaceInGlobal( )

Tim Rymer16-Jan-02 9:04

Tim Rymer

16-Jan-02 9:04

FINISHED!

Tim Rymer16-Jan-02 10:33

Tim Rymer

16-Jan-02 10:33

i got it working. who knows how, but if anyone else has this problem i can work with anyone now about it. i know what to do now. thanks a bunch.

~Timothy T. Rymer

www.digipen.edu
tim.xpertz.com

Re: FINISHED!

Joao Vaz16-Jan-02 22:35

Joao Vaz

16-Jan-02 22:35

Good for you Tim Rymer Big Grin | :-D

COM it's a beast to learn ,I readed 8 books on COM/ATL to be proficient

Regards and happy COM coding

Joao Vaz

How to set the identity user of a COM component

xicoloko16-Jan-02 2:28

xicoloko

16-Jan-02 2:28

Hi,

How to set the identity user of a COM component using VC++? Confused | :confused:

Thanks,
- xico -

CAxDialogImpl<> and MS Word macro

MECVA15-Jan-02 8:21

MECVA

15-Jan-02 8:21

Hi,

I created a dialog box using the ATL Object Wizard choosing the category Miscellaneous and the object type Dialog. The result of this action was a dialog implemented by a class that specializes the template CAxDialogImpl<...>. This dialog is showed in a method of another COM object created as SimpleObject. The SimpleObject component is instantiated in an MS Word macro. When I install my program in a machine without Visual C++ installed the program breaks down. I am sure that the COM support is installed, because when I run another component in the same way, but not using this kind of Dialog, the program does not break down. Can anybody help me?

Thanks in advance,

Márcio Azevedo.

Re: CAxDialogImpl<> and MS Word macro

Not Active15-Jan-02 9:09

Not Active

15-Jan-02 9:09

Make sure your components have been built in release mode not debug. Does your dialog use any controls that have been installed on the build machine but not on the target?

Re: CAxDialogImpl<> and MS Word macro

Michael P Butler15-Jan-02 22:21

Michael P Butler

15-Jan-02 22:21

How was the object compiled. Release Min Dependancy or Release Min-Size? Min-Size requires ATL.DLL to be registered on the system. What about the run-time library version it was compiled with, was it Multi-threaded. I've had some problems with systems missing msvcp60.dll

Michael Smile | :)

Connection Points with Variant Parameter

AndyC14-Jan-02 22:03

AndyC

14-Jan-02 22:03

I am try to pass a variant as a parameter on a connection point, but at the moment I am having little success.
Does any body have any idea if I can do this ?

Deleting the mutiple instances of COM object

Ebin14-Jan-02 19:52

Ebin

14-Jan-02 19:52

We have implemented a com client in VC++ and it should communicate with server that developed in Delphi(.dll).

The Scenario is as folows
-------------------------------------

A button click on com client(vc) will invoke the com server (Delphi interface).
which will display a dialog were user can interact.Thus by the button click on VC client can invok multiple instances of delphi server.

Now we need to delete or close all the instances of com server with a single click in vc client (com client)
how it is possible ?.

Also there is problem of how the com client (VC) should identify any event occured, on which delphi interface.
Is there any way of identifying it ?.

HTML Control Printing Problem

John Osborn14-Jan-02 16:29

John Osborn

14-Jan-02 16:29

If I use the ATL COM AppWizard to create an HTML Control and then embed it in a web page it shows up fine on the monitor, but never prints to the printer. Does anyone know what's going on with that? And while we are at it, the default HTML Control project generates a sample control with 3 buttons labeled Red, Green and Blue that when clicked generate the error "Object doesn't support this property or method". Has anyone else experienced this? Confused | :confused:

Calls to _IOutBound from several threads

Alvin77712-Jan-02 0:37

Alvin777

12-Jan-02 0:37

I have a VB application which uses COMponent written on VC++. COMponent implements IConnectionPoint and creates additional threads. Pointer to [source] interface _IOutBound is correctly marshalled between main thread and additional ones.
The problem arises when VB calls Release (and --m_Ref==0). COMponent waits for threads to end and VB cannot serve call to _IOutBound since it is waiting in COMponent. And if one of the threads calling for _IOutBound - I got deadlock.
How can I prevent that deadlock?

--
Alvin777

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