Re: Exception Handling Error - COM Discussion Boards

Amit Dey18-Jun-02 11:14

18-Jun-02 11:14

On the topic of sinking events, please take a look here. The project contains code that sinks events to a custom toolbar created thru an Office addin. Ofcourse it is a pure ATL project.

HTH,

You yard yellow years yieldingly; you yanked your yearning yoke.-Jeremy Falcon-CPite.

Amit Dey

sonork: 100:18407
msn: visualcdev

19-Jun-02 4:37

I have tried to implement something like that, using MSWord in place of Outlook and I cannot get it to work. It keeps giving me Link Errors because of duplicate IID_XXXX's. How do I get around this if I were to use pure ATL? Confused | :confused:

20-Jun-02 6:32

Try out various #import options keywords like no_namespace, rename etc to resolve link problem.

Anonymous27-Aug-02 9:15

Anonymous

27-Aug-02 9:15

Could you be a little specific and tell me what are the errors?

Amit Dey27-Aug-02 13:52

Re: Exception Handling Error

27-Aug-02 13:52

Yeah, I came across a similar duplicate IID problem while building Word addin. I know how frustrating this is!! Big Grin | :-D

If you already haven't figured out, the solution is to move the #import statement for importing Word typelib(the 2nd #import) to your addins .h file.

e.g. I put the following #imports in my Addin.h file. so it looks like :

#ifndef __ADDIN_H_
#define __ADDIN_H_

#include "resource.h" // main symbols

#import "D:\Program Files\Common Files\designer\MSADDNDR.TLB" raw_interfaces_only, raw_native_types, no_namespace, named_guids

#import "D:\Program Files\Microsoft Office\Office\MSWORD9.olb" rename_namespace("MSWORD"), rename("ExitWindows","WordExitWindows"), named_guids, raw_interfaces_only
using namespace MSWORD;

and then rebuild. Smile | :)

HTH,

'My capacity for happiness', he added, 'you could fit into a matchbox without taking out the matches first'.

- Marvin, the robot.

Amit Dey

sonork: 100:18407
msn: visualcdev

Exception Handling Error

soup15-Jun-02 6:00

soup

15-Jun-02 6:00

Hi,

I have a very simple program that is going to use ADO as the interface to a database.

I imported ADO in a wrapper class using the following line:

#import "C:\Program Files\Common Files\System\Ado\msado15.dll" no_namespace rename("EOF", "adoEOF")

My code to connect to the selected database looks like:

try
{
m_objConn.CreateInstance(__uuidof(Connection));
m_objConn->Open(strConn, strUser, strPass, m_lngConnOptions);
}
catch(_com_error &errConn)
{
m_strLastError = (char *) errConn.Description();
m_objConn = NULL;
}

If everything is fine so ADO can connect all is good. Smile | :)

However, when the connection fails (for any reason, such as bad connection string, DSN doesn't exist etc), I get the following error:

First-chance exception in MyDBApp.exe (MSVCRTD.DLL): 0xE06D7363: Microsoft C++ Exception.

I traced through the code, into the import .tli/.tlh file and the exception occurs in the call (or around the call) to _com_issue_errorex(...).

Has anyone ever encountered a problem with COM error handling like this before? If so, what is the solution, because so far the problem seems to lie with COM/ADO, not my application.

Under debug, the code continues, under release, it invalid page faults.

Please help!

Thanks in advance,

Simon

Tim Smith15-Jun-02 6:20

Tim Smith

15-Jun-02 6:20

This is perfectly normal. Anytime an exception is raised, you will get some type of "First-chance exception" message. The rest of the message is just saying that it is a C++ exception (the _com_issue_errorex).

You catch statement will catch the error and you can process it and handle it.

Don't worry about first-chance exceptions that you are handling properly.

Tim Smith

I know what you're thinking punk, you're thinking did he spell check this document? Well, to tell you the truth I kinda forgot myself in all this excitement. But being this here's CodeProject, the most powerful forums in the world and would blow your head clean off, you've got to ask yourself one question, Do I feel lucky? Well do ya punk?

Re: Exception Handling Error

soup15-Jun-02 14:25

soup

15-Jun-02 14:25

Tim,

Thanks for the response. I was obviously getting silly and became side-tracked by the (handled) unhandled exception! Big Grin | :-D

However, my crash under release remains. Not sure if you can help, but I tracked it down to a worker thread using a window pointer to send a message (using SendMessage). After peeking in the documentation (I have little threading knowledge), it says windows handles are unreliable.

If this is the case, how can my thread tell the child frame it is running in that it has completed?

Thanks for any help,

Simon

Re: Exception Handling Error

Tim Smith15-Jun-02 14:58

Tim Smith

15-Jun-02 14:58

You should be able to use the REAL window handle (as in HWND). Windows is smart enough, to thunk the SendMessage over to the proper thread. It is just that you can't use CWnd points.

One thing you can do is build your release build with debug information. This will allow you to run the optimized code in the debugger. Looking at local variables will be very hit or miss (and sometimes will just flat out tell you the wrong thing), but it might help to track down the problem.

Tim Smith

I know what you're thinking punk, you're thinking did he spell check this document? Well, to tell you the truth I kinda forgot myself in all this excitement. But being this here's CodeProject, the most powerful forums in the world and would blow your head clean off, you've got to ask yourself one question, Do I feel lucky? Well do ya punk?

How to pass out an array from a com+ object?

Lizp13-Jun-02 23:43

Lizp

13-Jun-02 23:43

I am developing an application which need to pass an
array from a com+ object to the client,the object runs at
the server and the client app runs at a workstation.the
problem is i can't get the actual array at the client's
side.
some represetative code follows:
//.idl
[id(15), helpstring("method GetAllPolicyID")] HRESULT
GetAllPolicyID([in,out]long* size,[out,size_is(,*size)]
long** PolicyID);
//.cpp
*size=pRst->RecordCount;
*PolicyID=(ULONG*)CoTaskMemAlloc(*size*sizeof(ULONG));
for(long i=0;i<*size;i++)
{
if(!pRst->adoEOF)
{
vt=pRst->GetCollect("POLICYID");
(*PolicyID)[i]=vt.lVal;
pRst->MoveNext();
}
}

Scratch

Re: How to pass out an array from a com+ object?

soptest14-Jun-02 9:40

soptest

14-Jun-02 9:40

You must produce a proxy-stub DLL by compiling and linking the C files produced by MIDL. The ATL AppWizard produces a make file called projectps.mk to do this. You must make sure that your server does not register its component's interfaces as type library marshaled with the automation marshaler because automation does not recognize the array attributes. (marshaling done by custom marshaler in your proxy/stub DLL)

soptest

Re: How to pass out an array from a com+ object?

Lizp14-Jun-02 16:09

Lizp

14-Jun-02 16:09

Thank for your help!
And how to avoid registerring the interfaces as automation marshaler?

Scratch

Please help (Events)

Jason Troitsky (was Hattingh)13-Jun-02 21:30

13-Jun-02 21:30

Hi there,

I have a simple ATL project (with MFC support) as generated by the wizard. I have a simple ATL object created, with nothing changed in the settings presented by the ATL wizard dialog box.

This object has "Start()" and "Stop()" methods which work fine when I test them in a VB app.

What I would LIKE to do now is be able to fire an event (is this correct terminology?), so that when in VB a subprocedure will run/fire when something in my COM dll decides it should.

How do I set about doing this?

TIA

Jason

Amit Dey15-Jun-02 5:55

15-Jun-02 5:55

Hi,
I think you might find the article here an interesting read.

sonork: 100:18407

You yard yellow years yieldingly; you yanked your yearning yoke.

-Jeremy Falcon

Jason Troitsky (was Hattingh)15-Jun-02 6:19

15-Jun-02 6:19

Thanks Jeremy. I appreciate your feedback, but the article appears to explain the reverse of what I want to do. I need to teach my ATL object to raise an even for VB, not the other way around.

Jason

Amit Dey15-Jun-02 14:56

15-Jun-02 14:56

Hi Jason,
One cheap trick(and saving yourself a lot of heartache Smile | :)

) would be to rig up a method in your VB module that uses the RaiseEvent keyword to fire your event. You could then simply call this VB method from your VC component or client after you instantiate the object.

You yard yellow years yieldingly; you yanked your yearning yoke.-Jeremy Falcon-CPite.

Amit Dey

sonork: 100:18407
msn: visualcdev

Jason Troitsky (was Hattingh)15-Jun-02 22:28

15-Jun-02 22:28

I've since found info on events, etc (drGui article in MSDN)... and it's got me *sweating*...

This "cheap trick" you meantion sounds promising, but I cannot understand what you are explaining. Please break it down for me a bit further.

Thank you!

Jason

Amit Dey18-Jun-02 11:26

18-Jun-02 11:26

No sweat, Jason. Smile | :)

Here's what I meant. suppose you have a VB activex dll in which there is a class(your COM object) that implements some functionality. In it you have declared an event like:

Public Event evtHello(str As String)

What you'd like to do, as I understand, is fire such an event from a VC++ client or a VC++ COM object. While you can definately fire such an event thru Invoke(as it is a dispinterface), like regular ATL connection points do(the code is actually very similar to what the ATL Wizard adds), this would be the harder way. the easier way would be to fire/raise such an event thru a member method of your VB COM object(class) using the RaiseEvent keyword like:

Public Sub Hello()
RaiseEvent evtHello("Now")
End Sub

Now all that remains for your VC++ client to do is call this Hello VB method to fire the event. Please take a look at the related article
here for code to do this.

You yard yellow years yieldingly; you yanked your yearning yoke.-Jeremy Falcon-CPite.

Amit Dey

sonork: 100:18407
msn: visualcdev

Jason Troitsky (was Hattingh)18-Jun-02 11:42

18-Jun-02 11:42

That's very cool... I like it!

Thanks for taking the time to explain.

Jason

Amit Dey21-Jun-02 6:42

21-Jun-02 6:42

Hi,
I liked your DX static control. very cool. Are you planning a dx8 version?

You yard yellow years yieldingly; you yanked your yearning yoke.-Jeremy Falcon-CPite.

Amit Dey

sonork: 100:18407
msn: visualcdev

Jason Troitsky (was Hattingh)27-Jun-02 0:09