鼠标滚轮滚动事件 Chrome Firefox

// 判断浏览器
let mousewheelevt=(/Firefox/i.test(navigator.userAgent))?"DOMMouseScroll": "mousewheel"

if (document.attachEvent) {
  // 火狐
  document.attachEvent("on"+mousewheelevt, (e) => {
    // Balalalalala
  })
} else if (document.addEventListener) {
  document.addEventListener(mousewheelevt, (e) => {
    // Balalalalalal
  }, false) 
}