Is it bad to use servicelocation instead of constructor injection to avoid writing loads of factory classes

Question

Right now we use DI/IOC and when we need to pass extra parameters to a constructor we use a factory class e.g.

public class EmailSender 
{
    internal Email         


        

Answer 1

The largest reason I can think of (without just looking at issues with Service Locators in general) is that it is not what I as a user of your class would expect.

Meta discussion:
Some DI frameworks (Guice for example) will build the factory for you.

Some people advocate separating the "newable" from the "injectable".