代码示例

    1. class EventHub{
    2.   constructor(){
    3.     this.events = {}
    4.   }
    5.   on(type,handle){
    6.     this.events[type] = (this.events[type] || [] ).concat(handle)
    7.   }
    8.   emit(type,data){
    9.     this.events[type].forEach(handle=>handle(data))
    10.   }
    11.   off(type,handle){
    12.     if(!this.events[type]) return
    13.     if(!handle){
    14.       delete this.events[type]
    15.       return
    16.     }
    17.     let index = this.events[type].indexOf(fn)
    18.     if (index===-1) return
    19.     this.events[type].splice(index,1)
    20.   }
    21. }

    测试代码

    1. let eventHub = new EventHub()
    2. let fn1 = ()=>{console.log(1)}
    3. let fn2 = ()=>{console.log(2)}
    4. let fn3 = ()=>{console.log(3)}
    5. let fn4 = ()=>{console.log(4)}
    6. let fn5 = ()=>{console.log(5)}
    7. eventHub.on('event',fn1)
    8. eventHub.on('event',fn2)
    9. eventHub.on('event',fn3)
    10. eventHub.on('event',fn4)
    11. eventHub.on('event',fn5)
    12. eventHub.emit('event')
    13. eventHub.off('event',fn2)

    「@浪里淘沙的小法师」