UnityEvents

UnityEvents are a powerful feature within the Unity game engine that allow for the creation of event-driven systems. They act as a mechanism to decouple game logic, enabling different parts of a project to communicate with each other without direct dependencies. Essentially, a UnityEvent is a serializable list of listeners that can be invoked at runtime. This means you can define an event in one script and have multiple other scripts subscribe to that event, responding when it is triggered.

The primary use case for UnityEvents is to allow designers to hook up game logic directly in the Unity editor. For instance, a button in the UI can have a UnityEvent associated with it. This event can then be configured in the Inspector to call specific public methods on other GameObjects. This is incredibly useful for scenarios like triggering animations, playing sound effects, or changing game states in response to user input or in-game occurrences.

UnityEvents support different types of events based on the parameters they can pass to their listeners. There are no-parameter events, events that pass a single integer, float, string, or boolean, and even events that can pass a GameObject or a Unity object. This flexibility makes them adaptable to a wide range of game development needs. When an event is invoked, all registered listeners are called in the order they were added. This system promotes a more modular and maintainable codebase, as components can react to events without needing to know the specifics of what triggers them.