After some reading, i've gather .NET Remoting is a deprecated API which has been replaced by WCF.
I'm writing an automation framework, and would like to reference a DLL with types/methods either locally, or on some remote machine, and execute them without respect to where they are executing.
I thought Remoting is the way to go, since i guess all functionality is performed on a proxy object, making it irrelevant if it is a local object or remote.
How can WCF perform this kind of action (if at all) or .NET Remoting is the way to go ?
Or perhaps some other option i haven't thought of?
There is no magic way to call a method completely transparent without regards to which machine to run it on, as far as I know, including .NET Remoting. However, WCF makes extensive use of proxies, either generated automatically from WSDL documents or by directly referencing the types/interfaces from a shared dll.
Thus, you could create a shared dll containing some methods, add some WCF plumbing (i.e. creating a Service interface out of the methods/types you want to expose) and then decide whether to use them directly/locally in your project, or access them via a proxy. This makes it fairly easy to invoke methods remotely. Note however that you cannot create fully-fledged classes that expose state and functionality remotely, the memory holding the actual objects are not shared remotely, it is, after all, just a 'trick'.
Depending on your setup, you may:
Although it is easy to invoke remote methods, including sending/returning complex data structures, WCF internally creates a full communication stack, possibly consisting of lots of logic, including for example security, transaction and reliability. This means that remote communication comes with a cost, both stressing the CPU and the network.
A primer to WCF can be found here.
If you want more performance than possible with the built in communication options, you may want to consider using something like Google Protocol Buffers to both slim down the amount of data being transferred and to lower the CPU load.
For C# there are two implementations of Protocol Buffers that I know of, Protobuf CSharp by Jon Skeet and Protobuf-net by Marc Gravell.
A final note just to be clear; no, WCF does not give you a way to fully abstract away the location of types/methods.