.net architecture

Question

Hi I am re-engineering financial software and have the following design as of now. 1. Client in VB.Net -- Front End 2. Business Layer in VB.Net -- Middle Layer (Business Logic) 3. Data Access / Manipulation Components in Unmanaged C++ -- Back End Layer 4. Oracle 9i as database The client middle and back end layer will communicate via XML. My query is as follows: 1. How will these components talk to each other in Dot Net Environment? Specially Unmanaged C++ and VB.Net 2. Will it be beneficial to develop the Unmanaged C++ code in Visual Studio 6 and remaining in Visual Studio 7 or all of them should be developed in VS7? The reason for using Unmanaged C++ is to get power of C++ with respect to data manipulation and collections using STL. Which book should I buy in order to get the idea of DOT NET environment at the same time focus on Unmanaged C++? Thanks in Advance Regards

j.mikejenkins · Answer

1. You can use PInvoke to communite with your unmanaged C++ class. This is accomplished with the DllImportAttribute. Basically you create a class with static methods that correlate to the methods in the unmanaged DLL. 2. You can still write unmanaged C++ in the VS.NET. What I would do is create a managed C++ wrapper that delegates all your calls to the unmanaged DLL. This will allow your business logic layer to easily communicate with data layer because all the middle layer does is reference the MSIL of the data layer. Also the .NET framework has its own collections (ArrayList HashTable etc). I would consider it a waste for you to go unmanaged C++ just for the use of the STL.