Is that possible to call .net 2.0 com component fro .net 1.1application?

[aimlab08@gmail.com]

Hi all,

We have an application which is created in .net 1.1(Visual studio
2003). Now we need to create maps from this application. The only
chioce for us is to use ESRI libraries to generate map images.

The issue is, current version of ESRI (ArvGIS 9.2) only support .net
2.0. I wrote a map component with Visual studio 2005, and check the
"Register for COM interop" for the project. This creates both dll and
tlb assemblies.

I was not able to add this com component to my .net 2003 application
as reference. When I tried to add the tlb file as the reference, I got
the following error message:

"A reference to "myMapCom" could not be added. Converting the type
library to a .NET assembly failed. Type library myMapCom was exported
from a CLR assembly and can not be re-imported as a CLR assembly."

Any idea for solving this issue?

Thanks.

Linda

[Jeroen Mostert]

Re: Is that possible to call .net 2.0 com component fro .net 1.1application?

aimlab08@gmail. com wrote:

We have an application which is created in .net 1.1(Visual studio
2003). Now we need to create maps from this application. The only
chioce for us is to use ESRI libraries to generate map images.
>
The issue is, current version of ESRI (ArvGIS 9.2) only support .net
2.0. I wrote a map component with Visual studio 2005, and check the
"Register for COM interop" for the project. This creates both dll and
tlb assemblies.
>
I was not able to add this com component to my .net 2003 application
as reference. When I tried to add the tlb file as the reference, I got
the following error message:
>
"A reference to "myMapCom" could not be added. Converting the type
library to a .NET assembly failed. Type library myMapCom was exported
from a CLR assembly and can not be re-imported as a CLR assembly."
>
Any idea for solving this issue?
>

First, you absolutely want to consider converting your 1.1 application to
2.0. There's no point clinging to VS 2003 and the 1.1 runtime, especially
since recent Windows installations don't have the 1.1 runtime at all and
simply run 1.1 assemblies in the 2.0 runtime as well (so you might as well
deal with the compatibility issues now). If the argument is that your
clients only have 1.1 installed: in that case, you cannot use 2.0 components
at all, so that would not seem to be an issue.

As you've discovered, direct COM interop between .NET assemblies isn't
supported (because .NET assemblies should call each other directly -- but
VS2003 can't handle 2.0 assemblies). You can use COM+ by deriving your 2.0
component from ServicedCompone nt and deploying it as a server, but this has
some runtime overhead.

One workaround could be to create a stub 1.1 assembly with empty
implementations and sign it with the same strong name as your 2.0 assembly.
You can then deploy the 2.0 assembly and set up binding redirection in the
app.config to force the runtime to load the new assembly instead. This works
only if the entire application is running under the 2.0 framework, and it
has some obvious maintenance problems. Disclaimer: I haven't tested this.

--
J.