code: function bindBtn () {
        ele.querySelector('.mip-carousel-preBtn').addEventListener('click', function (event) {
          /* istanbul ignore if */
          if (!btnLock.stop) {
            return
          }
  
          btnLock.stop = 0
  
          imgIndex = imgIndex - 1
  
          clearInterval(moveInterval)
          move(wrapBox, imgIndex + 1, imgIndex)
          if (isAutoPlay) {
            autoPlay()
          }
        }, false)
  
        ele.querySelector('.mip-carousel-nextBtn').addEventListener('click', function (event) {
          /* istanbul ignore if */
          if (!btnLock.stop) {
            return
          }
  
          btnLock.stop = 0
  
          imgIndex = imgIndex + 1
          clearInterval(moveInterval)
          move(wrapBox, imgIndex - 1, imgIndex)
          if (isAutoPlay) {
            autoPlay()
          }
        }, false)
      }
docs: 绑定按钮切换事件