防抖和节流

// 防抖和节流
// 使用方法：
// let exportFunct = throttle(this.exportExcel,5000)
// exportFunct(传参数)
// 如果没有参数:exportFunct()
export function debounce(fn, wait) {
  return function(args) {
    //获取函数的作用域和变量
    let that = this
    let _args = args
    //每次事件被触发，都会清除当前的timer，然后重写设置超时调用
    clearTimeout(fn.id)
    fn.id = setTimeout(function() {
      fn.call(that, _args)
    }, wait)
  }
}

export function throttle(fn, wait, delay) {
  let last,
    deferTimer = null
  return function() {
    let that = this
    let _args = arguments
    let now = +new Date()
    if (last && now < last + delay) {
      clearTimeout(deferTimer)
      deferTimer = setTimeout(function() {
        last = now
        fn.apply(that, _args)
      }, wait)
    } else {
      console.log(32, 3222)
      last = now
      fn.apply(that, _args)
    }
  }
}