实现一个最简单的event管理类

class Event {

            constructor() {

                this.lists = {}

            }

            on(name, fn) {

                this.lists[name] = fn

            }

            trigger(name) {

                this.lists[name]()

            }

            off(name) {

                delete this.lists[name]

            }

        }

        let instance = new Event()

        instance.on("lock", () => {

            console.log("lock")

        })

        instance.trigger("lock")