Writing COM component in C#

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Jan Eliasen - 21 Sep 2005 13:41 GMT

Hi

I am terribly sorry to disturb you all with this probably very simple
question... but I have searched the net for two hours, and there are a
lot of webpages out there with the words n it that I have tried
searching for :-/

Anyway, I need a simple quick guide to how I cna write a dll in C#
that I can register as a COM component and then I'd like to call it
from my VBA application in Visio.

I have started Visual Studio ..NET 2003

I have created a new project as a class library

I have entered "Register for COM Interop" in the projects properties

I have entered "[ComVisible(true)]" just above both the class
statement and just above two different methods.

I have written "[ClassInterface(ClassInterfaceType.AutoDispatch)]"
just above the class statement

And I have written
"[GuidAttribute("FE250E36-0897-4a15-ADEF-CA69CD71B8CD"),
ProgId("WM_data.DK.Axapta.Axapta_CAD_Integration.Axapta_CAD_Integration")]"
just above the class statement.

When I compile my code, nothing fails, and in the registry I can now
see my component. Allthoug I have no idea whether is is registered the
right way :-)

In my VBA code in the Visio Macro, I have a line called this:
Set obj =
CreateObject("WM_data.DK.Axapta.Axapta_CAD_Integration.Axapta_CAD_Integration")

It does not fail, leaving me to think that my component is actually
registered correctly. But the error comes when I want to call a
method, ie:
obj.ReceiveDataAndSendItToAxaptaASync (str)

This IS the correct name of the method, and it takes a string as a
parameter. The error I receive is "Object doesn't support this
property or method".

So I must have done something wrong.

Help?

Signature

Jan Eliasen, representing himself and not the company he works for.

Reply to this Message

Bob - 21 Sep 2005 14:05 GMT

> Hi
>
[quoted text clipped - 17 lines]
>
> I have written "[ClassInterface(ClassInterfaceType.AutoDispatch)]"

It is better and recommended in MSDN that you should not use AutoDispatch
but I doubt this is the cause.

> just above the class statement
>
[quoted text clipped - 15 lines]
> method, ie:
> obj.ReceiveDataAndSendItToAxaptaASync (str)

Can you post the exact signature of this? Does your COM component uses other
.Net Assemblies?

> This IS the correct name of the method, and it takes a string as a
> parameter. The error I receive is "Object doesn't support this
[quoted text clipped - 3 lines]
>
> Help?

Reply to this Message

Jan Eliasen - 21 Sep 2005 14:20 GMT

>> I have written "[ClassInterface(ClassInterfaceType.AutoDispatch)]"
>It is better and recommended in MSDN that you should not use AutoDispatch
>but I doubt this is the cause.

Should I remove the line or replace it with something else?

>> In my VBA code in the Visio Macro, I have a line called this:
>> Set obj =
[quoted text clipped - 6 lines]
>Can you post the exact signature of this? Does your COM component uses other
>.Net Assemblies?

The signature is this:
public static void ReceiveDataAndSendItToAxaptaASync(string xml)
The method takes the string, loads it into an XMLDocument. Then the
content of one of the nodes in the xml is written to a file on the
c-drive.

Signature

Jan Eliasen, representing himself and not the company he works for.

Reply to this Message

Jan Eliasen - 21 Sep 2005 14:56 GMT

>Can you post the exact signature of this? Does your COM component uses other
>.Net Assemblies?

Hi

I have it working now.

I removed the "[ClassInterface(ClassInterfaceType.AutoDispatch)]" as
you told me, and I changed the methods from being static to being
"normal" - now it works.

Thanks for your time.

Signature

Jan Eliasen, representing himself and not the company he works for.

Reply to this Message

Kaustav. - 22 Sep 2005 15:16 GMT

Hi Jan,

does your class library have a parametrized constructor ? If yes, try using
a constructor with no parameters and see if it works.

> Hi
>
[quoted text clipped - 44 lines]
>
> Help?

Reply to this Message

Jan Eliasen - 27 Sep 2005 10:06 GMT

>does your class library have a parametrized constructor ? If yes, try using
>a constructor with no parameters and see if it works.

Hi

No, it doesn't. But I solved the problem in another way, as you can
see previous in this thread.

Thanks, though :-)

Signature

Jan Eliasen, representing himself and not the company he works for.