To share a user control between different modules without having hard references between them you can do the following:
Create a common Interfaces project to put the interface of your User Control. This project will be referenced by all the modules that want to use the User Control.
Create a module that implements the interface of your User Control. Then, register in the container a type mapping between the interface and the concrete class implementation of your User Control as follows:
Define a module dependency from the modules that use the User Control to the one that implements it and registers the type mapping. If Module A has the interface and Module B will implement the view, you could
write the following in case you were using the Configuration Module Enumerator.
Get an instance of the User Control using the container through the its interface as follows.
The following articles give some more information about some of the topics mentioned above.
About type mapping:
Unity Application Block Methods
About module dependencies:
Using the Directory Lookup Module Enumerator
Using the Configuration Module Enumerator
Please let me know if this helps.