CancellationToken.Register Method (Action)
Registers a delegate that will be called when this CancellationToken is canceled.
Assemblies: System.Threading.Tasks (in System.Threading.Tasks.dll)
mscorlib (in mscorlib.dll)
If this token is already in the canceled state, the delegate will be run immediately and synchronously. Any exception the delegate generates will be propagated out of this method call.
The current ExecutionContext, if one exists, will be captured along with the delegate and will be used when executing it.