Migrating From RDC to .NET (CR 2008)

[Former Member]

Hello. I am anticipating updating our VB6-based product from using RDC (craxdrt.dll) components to support CR 2008.

I realize this means wrapping a .NET CR assembly using COM Interop so that it will continue to work with our existing VB6-based product. I don't know if the CR 2008 .NET-based object model will expose interfaces with the same methods and objects as in the VB6 RDC components.

We have very simple use of RDC, for example instantiating "Report" objects and setting some formulas from within our code. Is there developer documentation available to explain migrating RDC-based applications to the .NET-based 2008 edition?

Thanks for any assistance.

[former_member11696 · Accepted solution]

Hello,

No, the RDC is not supported at all in .NET. There is no one to one match, API order is the same but the code is completely different.

When you install CR 2008 you'll get a link on the start page to get to the Help and sample folders from our Support site.

If it's basic API functionality you are using there are lots of samples available.

[Here|https://boc.sdn.sap.com/] is another link to our Diamond support site.

[Former Member · Accepted solution]

Hi Don,

Thanks for the reply, but I don't fully understand your response.

I don't intend to try to continue to use RDC within CR 2008. Rather, I want to know if I wrap a CR 2008 component through COM interop to look like a COM dll, are the public interfaces similar to their RDC ancestors, so that I can just "plug" the wrapped component into my app in place of the old craxdrt.dll (of course, changing the references within the affected modules)? So, for example, is there a "Report" object exposed in the .NET component that I can instantiate the same as with the older RDC component?

Also, if I do wrap the .NET component with COM interop, are all of the public interfaces automatically exposed? I'm trying to determine how much, if any, code I will need to write on the .NET side.

Thanks for your help.

[former_member11696 · Accepted solution]

Hi Eman,

Bottom line is no and it's not something we can support or help you with. COM was kind of deprecated by Microsoft and they move everyone to .NET framework and Managed code. Bridging the two is and can cause problems with memory structures and object models. It's not something we can help you with and moving forward you will need to move to .NET fully to support both CR and your app anyways.

I suggest you discuss with your Prioject team on how to migrate to .NET fully.

Thanks agian

Don

[Former Member · Accepted solution]

COM is not deprecated. Of course Microsoft want to push the world into .Net, but it is really sad that the RDC is not supported in Crystal 2008 anymore.

Our MFC application must now use a COM wrapper to access the .Net wrapper which uses the Crystal .Net Assembly to set some parameters and print a report. Crystal .Net is then using another wrapper to access their unmanaged dlls. Very efficient!

[former_member183750 · Accepted solution]

As far as MS is concerned COM may not be deprecated, but RDC was deprecated with lots of notice in version 11 of Crystal Reports (with no complaints at the time) and is now retired in version 12 (2008).

Ludek