.NET Interop: Getting COM and .NET to Work Together
Rob Windsor, G6 Consulting
http://www.g6consulting.com
One of the biggest shocks many developers have when they first start exploring
VB.NET was that the .NET framework does not use COM. The developer community
is heavily invested in COM, they have spent a massive amount of time and effort
creating components that they need to continue to use. The .NET developers at
Microsoft understood this and thus they created tools that allow COM and .NET to
interoperate. Understanding how to use these tools and identifying related
issues will be the focus of this session.
While VB.NET is in its infancy we will mostly be concerned with getting access
to our legacy COM components in our VB.NET applications. We will review the
several options we have using both Visual Studio as well as the .NET framework's
command line tools. We will also discuss issues that garbage collection presents
when using COM components and how to properly deal with them.
Looking at the other side of the coin, because VB 6.0 applications, especially
front-end applications, do not easily migrate to VB.NET it is the common opinion
that VB 6.0 will continue to be used for years in the future. Existing applications
written in VB 6.0 will continue to be maintained and enhanced using VB 6.0 and may
never be migrated. The issue this presents is that as our VB.NET component code
base grows there will be times when you want a VB 6.0 application to be able to
access those components. Once again we will explore the different tools available
to assist us in doing this.