COM Objects on Windows 7 with 4.7.2

[schnitzel]

How exactly did you register this COM object on the new machine? Did you use regsvr32?

btw: looking at the info on DYMO website regarding COM class factory...

http://developers.dymo.com/2010/06/2...class-factory/

they also have .NET samples - I suggest you try that first as I believe your troubles are not related to Qt at all but I have to agree that it is weird if you get it working by taking it out of the constructor.

[kwire]

schnitzel

I didn't need to use regsvr32 because there was an install program.

The COM objects work because their software, a label designing application, works and prints using the same objects.

It works in my application too, if I take the constructor out of the form constructor. Now that is strange....

I saw those notes on the DYMO support site too, thanks for looking.

Have I tried it on .NET? No I was a Clipper programmer back in the days of DOS, then moved to Delphi for years. I used .NET and C# on one project, but never really got comfortable with it.

I like Qt a lot, but there is a learning curve with any software and the older I get the longer it takes me to get around the corner...

Thanks, Keith

[high_flyer]

Just a small comment:
I don't see where you are deleting 'dymoAddIn' and 'dymoLabels'?

I tried stepping through the debugger and I get lost in all the "Ax" code.

try setting a break point in the constructor, and just let it run, see if the break point gets caught.
It looks like this code is not getting called (for what ever reason) where it is.

[kwire]

schnitzel,

I downloaded and installed VB express. Tried it on the DYMO .NET VB example included in the SDK. After it converted the project it compiled it and ran just fine. I was able to open the label, fill in the data fields and it printed my labels including the barcode. So I guess the COM objects are registered and working OK.

I still can't think of a good reason I have to take the COM object instantiation out of the constructor. This project has a Main Form where I call each job from the menu by creating another form where I do the work and print my labels. Something in Qt must need to be done in the constructor before I can create these two COM objects.

I hate it when I don't know what is going on...

Keith

high_flyer,

I may be wrong, but I thought COM objects were reference counted and didn't need to be manually deleted. At least that is the way they always worked in Delphi and C#. When the last variable went out of scope that referenced the COM object the object was automatically deleted.

Is that not true for Qt?

Keith

[schnitzel]

Do they provide a C++ example? If so, are they also allocating the objects using new in the constructor?

[kwire]

schnitzel,

They have a Visual C++ example but they use CreateDispatch().

I took my inspiration for my code from the Qt dumpcpp documentation I found here.

I have tried lots of things and read lots and I think my usage is correct, it just won't work in the constructor of the form...

Keith

[high_flyer]

I may be wrong, but I thought COM objects were reference counted and didn't need to be manually deleted. At least that is the way they always worked in Delphi and C#. When the last variable went out of scope that referenced the COM object the object was automatically deleted.

Is that not true for Qt?

It has nothing to do with Qt.
Regarding the reference count on COM objects, I think it depends on what kind of pointer container they are held.
CComXXX<T> pointer does ref counts, but a plain pointer does not.
I can't see the declaration of the pointer variable so I don't know for your case.

You should run you application through a leak detection tool, which can also detect COM leakages to be sure.
I'd recommend that you ask that on a COM oriented forum, where the people know these issues in more detail.

[kwire]

high_flier, can you recommend a good "leak detection tool" that works on Windows 7?

[high_flyer]

You need more the just a leak detection tool, you need one that can also detect COM leaks (which (can be)/is trickier).
For "regular" leak detection you can use the CRT leak detection tool:
http://msdn.microsoft.com/en-us/libr...=vs.71%29.aspx
In my company we use our own brewed leak detection (which basically intercepts ALL (external as well) allocations/frees before the kernel) since we didn't find anything that could handle our large code base.
Again, you should ask that on forums that specialize with COM.

[schnitzel]

Taking one of their samples to try it on .NET shouldn't be too hard. You could try VB express (for free) which is very similar to Delphi. Anyway, the point is not to push you away from Qt, but to quickly try something that will show whether or not *their* stuff works.
If they have examples for C++, then I would try to follow that as closely as possible.
The fact that their software works might be because they do things programmatically - such as the registering a dll.

The link I sent had a lot of posts below the article where people were having tons of trouble with registration - that didn't look good