No. Because Android and iOS are different operaring systems.
The program flow is different, some views are similar but others are different, so you need to rewrite the code for those.
Almost all code not in relationship with the operating system can be imported without changes.
I am in the middle of porting a small app. As Klaus said, Android and IOS are two different beasts, once you start to get to grips with the ios program structure it's really not that difficult. Erel has done a great job on the one for one views and functions, which makes it easier for someone who knows B4a to get to grips with B4i.
My app is 16,000 lines in B4A and I'm going to port it over to B4I. Never having done this I don't know what percentage of the code will be common and what will be unique. For an app this size do you think it would be practical to share the code base and use #If B4A \ #If B4I? I notice you opted not to take that approach for things like DBUtils and KeyValueStore. What approach would you recommend?
You should find the modules that can be shared between the two projects and put them in the shared modules folder. Then you should use the conditional compilation symbols when you need make modifications based on the platform.
For the main UI related modules it is probably better not to share the same module.