Working with a VB COM Component

[David C]

This is my first time having to integrate a COM component into my
dotnet project. The COM component is from a VB developer, so I have
no control over his code.

I am having the following issues after importing the COM object into
Visual Studio (2003, not 2005).

When I create an instance of a class (Jobs jobs = new Jobs()), I get
the following error message.

COM object with CLSID {6FC1CF2C-BC59-4B78-AF18-B162F2D12CA6} is either
not valid or not registered.

Also, I expected the property I needed (Let's call this UserID) to be
a string. But its datatype is System.IntPtr. Huh? What is that?
But then when I force a string and compile just to see, I get the
following compilation error.

Property, indexer, or event 'UserId' is not supported by the language;
try directly calling accessor method
'OdysseyCO._Pet roToolsJobs.set _UserId(ref string)'

Now that's interesting. So I followed the recommendation and
tried .set_UserId(ref string). .set_UserId does not show up in my
intellisense, but the code compiles!

So unless there are other things I should try (can't imagine there are
any), what should I tell the VB developer?

[Willy Denoyette [MVP]]

Re: Working with a VB COM Component

"David C" <profnachos@gma il.comwrote in message
news:1174809711 .795443.311750@ d57g2000hsg.goo glegroups.com.. .

This is my first time having to integrate a COM component into my
dotnet project. The COM component is from a VB developer, so I have
no control over his code.
>
I am having the following issues after importing the COM object into
Visual Studio (2003, not 2005).
>
When I create an instance of a class (Jobs jobs = new Jobs()), I get
the following error message.
>
COM object with CLSID {6FC1CF2C-BC59-4B78-AF18-B162F2D12CA6} is either
not valid or not registered.
>
Also, I expected the property I needed (Let's call this UserID) to be
a string. But its datatype is System.IntPtr. Huh? What is that?
But then when I force a string and compile just to see, I get the
following compilation error.
>
Property, indexer, or event 'UserId' is not supported by the language;
try directly calling accessor method
'OdysseyCO._Pet roToolsJobs.set _UserId(ref string)'
>
Now that's interesting. So I followed the recommendation and
tried .set_UserId(ref string). .set_UserId does not show up in my
intellisense, but the code compiles!
>
So unless there are other things I should try (can't imagine there are
any), what should I tell the VB developer?
>

[Willy Denoyette [MVP]]

Re: Working with a VB COM Component

"David C" <profnachos@gma il.comwrote in message
news:1174809711 .795443.311750@ d57g2000hsg.goo glegroups.com.. .

This is my first time having to integrate a COM component into my
dotnet project. The COM component is from a VB developer, so I have
no control over his code.
>
I am having the following issues after importing the COM object into
Visual Studio (2003, not 2005).
>
When I create an instance of a class (Jobs jobs = new Jobs()), I get
the following error message.
>
COM object with CLSID {6FC1CF2C-BC59-4B78-AF18-B162F2D12CA6} is either
not valid or not registered.
>
Also, I expected the property I needed (Let's call this UserID) to be
a string. But its datatype is System.IntPtr. Huh? What is that?
But then when I force a string and compile just to see, I get the
following compilation error.
>
Property, indexer, or event 'UserId' is not supported by the language;
try directly calling accessor method
'OdysseyCO._Pet roToolsJobs.set _UserId(ref string)'
>
Now that's interesting. So I followed the recommendation and
tried .set_UserId(ref string). .set_UserId does not show up in my
intellisense, but the code compiles!
>
So unless there are other things I should try (can't imagine there are
any), what should I tell the VB developer?
>

How does the COM interface and coclass definition looks like when using oleview.exe on the
typelib?
Are you sure you have registered the correct dll before importing? Try to re-register the
dll using regsvr32.exe

Willy.

[David C]

Re: Working with a VB COM Component

>
How does the COM interface and coclass definition looks like when using oleview.exe on the
typelib?

I did look at it using oleview and the class I am interested in should
have a property called UserID, but it is listed as a method. This is
what it looks like.

[id(0x6803000e), propput]
void UserId([in, out] BSTR* rhs);

I don't have the slightest idea what I am looking at. I asked the VB
developer to just make it a string property (UserID, that is), but I
don't know what oleview is telling me.

Are you sure you have registered the correct dll before importing? Try to re-register the
dll using regsvr32.exe

After I posted, I did just that and I am not getting the "COM
object ....not registered" error any more. I thought I could treat
the interlop assembly like any other .NET assemblies, but I guess
not. The memories of DLL registration hell coming back...

[Willy Denoyette [MVP]]

Re: Working with a VB COM Component

"David C" <profnachos@gma il.comwrote in message
news:1174901433 .342875.234280@ n76g2000hsh.goo glegroups.com.. .

>

>>
>How does the COM interface and coclass definition looks like when using oleview.exe on
>the
>typelib?

>
I did look at it using oleview and the class I am interested in should
have a property called UserID, but it is listed as a method. This is
what it looks like.
>
[id(0x6803000e), propput]
void UserId([in, out] BSTR* rhs);
>
I don't have the slightest idea what I am looking at. I asked the VB
developer to just make it a string property (UserID, that is), but I
don't know what oleview is telling me.
>

>Are you sure you have registered the correct dll before importing? Try to re-register the
>dll using regsvr32.exe

>
After I posted, I did just that and I am not getting the "COM
object ....not registered" error any more. I thought I could treat
the interlop assembly like any other .NET assemblies, but I guess
not. The memories of DLL registration hell coming back...

A COM dll stay's a COM dll, and must be registered, this has nothing to do with .NET. Note,
that I don't know how you were able to set a reference to a non-registered COM DLL though,
you must have done something wrong.
The UserId property is passing a BSTR (Basic String), which will be marshaled as a CLI
Object.String by the COM interop marshaler when returned from COM. That means that a
'string' is the correct type for the property in C#.


Willy.

[David C]

Re: Working with a VB COM Component

>
A COM dll stay's a COM dll, and must be registered, this has nothing to do with .NET. Note,
that I don't know how you were able to set a reference to a non-registered COM DLL though,
you must have done something wrong.

I did Project->Add Reference. Clicked on the Com tab, clicked
"Browse" and found the COM dll and just imported it that way. From
there, I was able to use it.

The UserId property is passing a BSTR (Basic String), which will be marshaled as a CLI
Object.String by the COM interop marshaler when returned from COM. That means that a
'string' is the correct type for the property in C#.
>

MyClass.UserId does not compile. I cannot read it or assign a value
to it. And in .NET, the data type is System.Inptr, not string.