I'm interested in techniques people are using to support their products for both 9.3.1 and 10 users. Here's what I'm doing:
1. Creating VMware snapshots with 9.3.1 and 10 so I can test in both environments.
2. Develop in snapshot with ArcGIS 10 installed; created 2 projects, one with references to the 9.3.1 assemblies that I copied to a folder that I am using HintPaths in the vbproj to pick up. The ArcGIS 10 project refers to the v10 assemblies and I'm using a compiler variable ArcGIS10=True in that project, with it set to false in the 931 project. This way I can share the same code files with both projects, and use #If ArcGIS10 Then for any statements using new v10 functionality that would have prevented building it for 9.3.1. This way I can build both the 9.3.1 assembly and 10 assembly from the same machine.
3. Install - Using Wise for Windows Installer custom actions to determine the version of ArcGIS installed on the machine. I then have a separate feature for each assembly in the setup project, and then use the variable set by the custom action to set the initial feature install states.
I'd love to be able to use the new add-ins for v10, but it seems like it would be much more involved if I need to keep supporting 9.3.1.
Please share if you're in the same boat.
