Unreal Engine 4 Scripting with C++ Cookbook

Exposing multi-cast delegates to Blueprint

Multi-cast delegates are a great way to broadcast an event to multiple objects who listen or subscribe to the event in question. They are particularly invaluable if you have a C++ module that generates events that potentially arbitrary Actors might want to be notified about. This recipe shows you how to create a multi-cast delegate in C++ that can notify a group of other Actors during runtime.

How to do it…

1. Create a new StaticMeshActor class called King. Add the following to the class header:

   DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FOnKingDeathSignature, AKing*, DeadKing);

2. Add a new UFUNCTION to the class:

   UFUNCTION(BlueprintCallable, Category = King)
   void Die();

3. Add an instance of our multicast delegate ...