Import librfc32.dll by reflection

Question

Hi .net Specialists,
hope anyone can help.
I`d like to connect a external program with SAP. The external program provides a scripting interface to add custom VB.NET code. But it`s not possible to add own assembly references.
The program vendor told me, that the only way to use custom dll`s are to use the system.reflection function.
Did anyone know how this reflection function works and how i can use the librfc32.dll with this function?
Thanks,
Anton

Answer 1

Hi,
You should probably be using the SAP.Connector.dll and SAP.Connector.Rfc.dll assemblies, not the librfc32.dll by itself... At least, it will be way easier.
You need to put those 2 dlls in your Global Assembly Cache, or in the project's folder (either as reference, easier, or just the files). The "librfc32.dll" itself needs to be in the project's folder (with the .exe.).
I tested this (since I was curious) and you can just put the 3 dlls in your application folder, it works fine.
Once that is done, if you still need to load through reflection, google it, there's plenty of examples on the .Net. Basically, it works like this. I tested this code on a Windows 7 64 bit, without VS.NET 2003/2005 and without the .NET connector installed and it works.
// load assembly
System.Reflection.Assembly assm = System.Reflection.Assembly.LoadFrom("SAP.Connector.dll");
// define the client type
System.Type sapClientType = assm.GetType("SAP.Connector.SAPClient", true);
System.Type sapConnectionType = assm.GetType("SAP.Connector.Connection", true);
// initialize a client
object oSAPClient = System.Activator.CreateInstance(sapClientType);
// open the connection
System.Reflection.PropertyInfo connectionProp = sapClientType.GetProperty("Connection");
System.Reflection.PropertyInfo connectionStringProp = sapClientType.GetProperty("ConnectionString");
connectionStringProp.SetValue(oSAPClient, "AHOST=123...", null);
object conn = connectionProp.GetValue(oSAPClient, null);
System.Reflection.MethodInfo connectionOpen = sapConnectionType.GetMethod("Open");
object result = connectionOpen.Invoke(conn, null);
// do your stuff
// close the connection
System.Reflection.MethodInfo connectionClose = sapConnectionType.GetMethod("Close");
connectionClose.Invoke(conn, null);
Doing this is not trivial and requires a lot of effort. But you asked, so there you go!
Regards,
Michel
P.S. This is c# code, but VB.NET is very similar, only syntax is different but the logic is the same.
Edited by: Michel Roberge on Nov 18, 2010 8:23 PM
Edited by: Michel Roberge on Nov 18, 2010 9:09 PM