js使用setTimeout实现淡入淡出效果

QQ群招募中：646258285（招募中，没几个人说话），
需要交流的朋友可以直接加我微信( DntBeliv )或QQ( 1121864253 )

注意setTimeout是异步执行的，因此需要用递归的办法实现

const TIME0_in = 800  //ms
const TIME_delay = 40 //ms
const opacityDelay = TIME_delay/TIME0_in
let that = this
let i = 0;
function changeOpacity(){ 
  if(i>=TIME0_in/TIME_delay){
    console.log("2")
    this.opacity = 1
    return ;
  }
  that.opacity = 1-opacityDelay*i
  setTimeout(()=>{
    changeOpacity()
  },TIME_delay)
  i++
  console.log("1")
}
changeOpacity()

标签：const,淡入淡出,TIME0,js,delay,changeOpacity,TIME,setTimeout
来源： https://blog.51cto.com/u_15262460/2882611