C# scripts and the UI Event System in Unity
EventSystem is a mechanism for sending events to objects in a game that supports keyboards, mice, screen touches, and so on. EventSystem consists of multiple modules for sending events. If there is no EventSystem object in the scene, then, when creating a canvas, an EventSystem object will be automatically created along with it.
Figure 3.36 – EventSystem
As shown in Figure 3.36, the Inspector window of the EventSystem object exposes very few functionalities. This is because EventSystem is designed as a manager for cooperation between various input modules.
It should be noted that there can be, at most, one EventSystem object in a scene. If there are multiple EventSystem objects in the scene, a warning message will be displayed, as shown in Figure 3.37:
Figure 3.37 – A warning message when there are multiple EventSystem objects
When the game is running, EventSystem will look...