dragSize自用（vue中使用，拖拽改变侧边栏宽度）

dragSize.js 

// eg: 

const touch = { lastTime: 0, interval: 300, startX: 0 }
let move = 0; let element; let min = 100; let max = 300
// move 是鼠标移动的距离，min和max是可拖动范围
function mousemove_(e) {
  if (!touch.init) return
  move = e.pageX - touch.startX
  element.style.width =
        touch.width + move + 'px'
  if (touch.width + move > max) {
    element.style.width = max + 'px'
  }
  if (touch.width + move < min) {
    element.style.width = min + 'px'
  }
}
function mouseup_() {
  if (!touch.init) return
  touch.init = false
  document.removeEventListener('mousemove', mousemove_)
  document.removeEventListener('mouseup', mouseup_)
}

export const dragSize = {
  bind: function(el, binding) {
    if (el) {
      element = el
      max = binding.value.max
      min = binding.value.min
      el.style.position = 'relative'
      const dom = document.createElement('DIV')
      dom.style.height = '100%'
      dom.style.width = '3px'
      dom.style.position = 'absolute'
      dom.style.top = '0px'
      dom.style.right = '0px'
      dom.style.cursor = 'col-resize'
      dom.style.backgroundColor = 'transparent'
      dom.style.userSelect = 'none'
      dom.style.touchAction = 'none'
      dom.addEventListener('mousedown', function(e) {
        const now = +new Date()
        if (now - touch.lastTime < touch.interval) {
          return (touch.init = false)
        }
        touch.init = true
        touch.startX = e.pageX
        touch.width = el.offsetWidth
        document.addEventListener(
          'mousemove', mousemove_,
          { passive: false }
        )
        document.addEventListener('mouseup', mouseup_)
      })

      el.appendChild(dom)
    }
  },
  unbind: function(el, binding) {
    document.removeEventListener('mousemove', mousemove_)
    document.removeEventListener('mouseup', mouseup_)
  }
}

main.js中引用

import { dragSize } from '_c/dragSize'
Vue.directive('dragSize', dragSize)

vue文件中使用