/**
   * 防抖函数 解决连续多次点击出错
   * @param event
   */
  function debounce(event) {
    if(timer){
      clearTimeout(timer)
    }
    timer=setTimeout(()=>{
      // console.log('timer')
      timer=undefined
      let e = event || window.event || arguments.callee.caller.arguments[0];
      if (e && e.keyCode == 40) { //下
        if (direction != 38) direction = 40;
      }else  if (e && e.keyCode == 37) { //左
        if (direction != 39) direction = 37;
      }else if (e && e.keyCode == 39) { //右
        if (direction != 37) direction = 39;
      }
      else if (e && e.keyCode == 38) { // 上
        if (direction != 40) direction = 38;
      }
    },100)
  }