Interfacing MS Access with an external DLL/COM object created in C#
I have an MS Access database and need to interface with a C# DLL that is about to be created for me (as a COM object). My C# guy has no experience in interfacing with MS Access, and I have only interfaced Access with COM objects that I have purchased (EASendMail etc).
We have run a few tests, and I can half interface with his test DLL (once referenced), but the Intelisense isn't working correctly. However, whilst I am sure that we can overcome that one easily enough, it's the return messages that I am struggling to get my head around. How do I tell Access to listen for them and then, trigger an event/function?
I know this is a little vague - but I could really do with some pointers to get started.
We have run a few tests, and I can half interface with his test DLL (once referenced), but the Intelisense isn't working correctly. However, whilst I am sure that we can overcome that one easily enough, it's the return messages that I am struggling to get my head around. How do I tell Access to listen for them and then, trigger an event/function?
I know this is a little vague - but I could really do with some pointers to get started.
ASKER
Thanks John. I agree that the reference issue will be the DLL side of things (as mentioned the c# developer is great in certain areas - but this is new to him). However, the big issue is how the DLL pushes information back into Access so that Access can do something. So, I guess we're looking for a guide/best-practices approach for .Net.
Initially, I wanted us to create a function that allowed users to press a 'Call' button on the Access DB and then monitor for the connection/returned signals being received. We have already created a service that can initiate the call from a command line prompt and then I get Access to periodically check an XML file, which has the end-of-call status. This does work - but, it's not slick and I want to be able to do more than just Call a number, so getting a way to send/receive signals cleanly is essential.
Initially, I wanted us to create a function that allowed users to press a 'Call' button on the Access DB and then monitor for the connection/returned signals being received. We have already created a service that can initiate the call from a command line prompt and then I get Access to periodically check an XML file, which has the end-of-call status. This does work - but, it's not slick and I want to be able to do more than just Call a number, so getting a way to send/receive signals cleanly is essential.
The Dll should return an object...then you should cast the object to the type you want it..
Put a breakpoint and check what you get in the Watch window
Put a breakpoint and check what you get in the Watch window
ASKER
Thanks again John - I understand what you are saying - but we can't seem to get that far. Do you know of any simplistic examples VBA/.NET/VBA?
Check this example here
How do I tell Access to listen for them and then, trigger an event/function?
The answer is you don't. Just like calling a function in VBA, you would get a return value. ie.
intRet = SomeFunction()
It's not class based processing where you'd create an object based on a class, and then potentially hook that into events with "With Events". It's more like calling something in the Win API.
Jim.
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ASKER
Thank you, everyone - sorry for the delay in coming back to you. That should give us enough information to move forward.
If you give a rough outline of what you want to accomplish along with some sample code it would be easier to get a useful answer.