ReSharper DevGuide

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Work with Signals

What you should know beforehand:

Examples (?):

Signal is a way for a class to provide notifications. Signals are very similar to C# events, nevertheless, there are differences that make them more suitable for use within ReSharper data flow infrastructure.

public class SignalEmitter { public ISignal<bool> SomethingHappened { get; } public SignalEmitter(Lifetime lifetime) { SomethingHappened = new Signal<bool>(lifetime, "SignalEmitter.SomethingHappened"); } public void MakeItHappen(bool arg) { SomethingHappened.Fire(arg); } } public class SignalListener { public SignalListener(Lifetime lifetime, SignalEmitter signalEmitter) { signalEmitter.SomethingHappened.Advise(lifetime, arg => MessageBox.ShowInfo($"Something happened and it's {arg}")); } }


  • Signals must implement the ISignal interface.
  • To “subscribe” a handler to a signal, use the Advise method. A signal allows any number of listeners.
  • Unlike C# events, you should not care about “unsubscribing” from a signal to prevent memory leak. When you “subscribe” to a signal via Advise, you also pass a lifetime. Once the lifetime is terminated, ReSharper will take care about “unsubscribing” by itself.
  • To fire the signal, use the Fire method.
  • Signals have much in common with IProperty.
  • Signals are perfectly suited for MVC concept when an event should be fired by a view.
  • In simple cases, when you need a signal only for notification purposes (with no payload), you can use the ISimpleSignal interface.
Last modified: 12 July 2017