RCW Example

The .NET solution loancalc.sln contains the following of interest:

• LoanCalc.cbl. This is the managed COBOL program. It uses the COM object comploan.dll.
• Interop.comploan. This is a reference to the COM object and is listed in the References folder of the project. It is the COM object's proxy assembly, which is generated by the project. It is marked with a warning triangle if you have not created the COM object yet.

  The source code for the COM object is not included in the project, because the source is remaining as unmanaged code. Only the built COM object is required within the project.

The COBOL application comploan\compdll.app contains the following programs:

• comploan.cbl. This is the existing OO COBOL source for the COM object. The code is based on the original CompLoan demonstration in Net Express. It has been updated to include a type library, which is required for COM objects in the .NET environment.
• comploanTrigger.cbl. The is the legacy trigger program. This is unchanged for interoperating with .NET.
• comploan\debug\comploan.dll. This is the built COM object. This is not shipped because you will create it when you compile the project.

To run the example:

1. In Net Express, compile the project compdll.app to create the COM object.
2. Register the COM object at a command prompt. To do this, go to the folder where you created the COM object, comploan.dll, and type:

   regsvr32 comploan.dll

3. In Visual Studio, close the solution loancalc.sln and reopen it to pick up the newly referenced COM object. You can see it now listed without the warning triangle.
4. Build the solution and step through it.