when I inherit an interface and impliment it,the interface is executed.How is it executed at the underlying code?For example , IPointerDownHandler
Interfaces just guarantee that variables and methods exist on the class. Thats all they do.
IPointerDownHandler is an Interface that Unity looks for when moving the pointer around. If your RectTransform has a component that implements that interface then whenever the pointer is clicked down on that object then it will call the method on your component.
After the pointer is clicked ,how IPointerDownHandler is executed? I want to ask is the middle of the process
Unity looks for components under the click that use the interface and calls the method on any found.
I’m not 100% sure that I understand your question, but the IPointerDownHandler is handled by Unity’s EventSystem, and call when it happens (on scripts that have it implemented).
I know, thank you
No problem.