Constructor error in WCF service implemented with Repository and UnitofWork patterns.

Answer 1

If you use default service instancing you must provide parameterless constructor. Your design provides dependency injection through constructor. In such case you must have your own instance provider to call the constructor and create service instance. You can create per service instance provider, behavior and optionally service host but it is really bad way. The better way is to use Inversion of Control container which will resolve your dependencies from configuration. In that case you will have only one new instance provider, behavior and optionally service host.

Here you have very nice post about creating new instnace provider which resolve services through Unity.