[UnityEditor.Callbacks.DidReloadScripts] # Unity Hot Reload（在进入PlayMode的时候，也会被调用）
[InitializeOnLoadAttribute] # 打开Editor时候执行（[待验证]进入PlayMode时会执行吗）。[文档]Allows you to initialize an Editor class when Unity loads, and when your scripts are recompiled.
EditorApplication.playModeStateChanged # Delegation