I have had cause for a write-only property.
In a .NET web-service, I have had to create a legacy ASMX web-service, as the URI is hard coded in hardware.
I'm a big fan of using Ninject for dependency injection, using constructor injection to satisfy all dependencies a class may have. For the most part, these dependencies would be declared private readonly fieldName and assigned to in the constructor. The reason for this is that the dependencies of the class are not part of the class' responsibilities; they are dependencies.
However, the problem is whatever factory mechanism ASP.NET uses to create the class instance for a web-service relies on there being a constructor with no arguments, that scuppered my constructor injection.
I could have used a call from the default constructor to re-direct to an overloaded constructor making use of a ServiceLocator (anti)pattern, but I didn't fancy that.
Using the Ninject web extension, I inherited my service class from Ninject.Web.WebServiceBase and employed property injection, marking the properties that Ninject would satisfy with an [Inject] attribute.
Getting back to the point about injected services being dependencies for the class, rather than responsibilities that the type has, I don't want these dependencies properties accessed by other classes, so I mark the get property as private.
