text: import Vue from 'vue'
  // v-dialogDrag: 弹窗拖拽属性
  Vue.directive('dialogDrag', {
    bind(el) {
      // console.log(binding, vnode, oldVnode);
      const dialogHeaderEl = el.querySelector('.el-dialog__header')
      const dragDom = el.querySelector('.el-dialog')
      dialogHeaderEl.style.cssText += ';cursor:move;'
      // dragDom.style.cssText += ';top:0px;' //修复每次top都是0
      dragDom.style.cssText += ''
  
      // 获取原有属性iedom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
      const sty = (function() {
        if (document.body.currentStyle) {
          // 在ie下兼容写法
          return (dom, attr) => dom.currentStyle[attr]
        } else {
          return (dom, attr) => getComputedStyle(dom, false)[attr]
        }
      })()
  
      dialogHeaderEl.onmousedown = e => {
        // 鼠标按下，计算当前元素距离可视区的距离
        const disX = e.clientX - dialogHeaderEl.offsetLeft
        const disY = e.clientY - dialogHeaderEl.offsetTop
        // body当前宽度
        const screenWidth = document.body.clientWidth
        // 可见区域高度(应为body高度，可某些环境下无法获取)
        const screenHeight = document.documentElement.clientHeight
  
        const dragDomWidth = dragDom.offsetWidth // 对话框宽度
        const dragDomheight = dragDom.offsetHeight // 对话框高度
  
        const minDragDomLeft = dragDom.offsetLeft
        const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth
  
        const minDragDomTop = dragDom.offsetTop
        const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomheight
  
        // 获取到的值带px 正则匹配替换
        let styL = sty(dragDom, 'left')
        // 为兼容ie
        if (styL === 'auto') styL = '0px'
        let styT = sty(dragDom, 'top')
  
        // console.log(styL);
        // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
        if (styL.includes('%')) {
          styL = +document.body.clientWidth * (+styL.replace(/%/g, '') / 100)
          styT = +document.body.clientHeight * (+styT.replace(/%/g, '') / 100)
        } else {
          styL = +styL.replace(/px/g, '')
          styT = +styT.replace(/px/g, '')
        }
  
        document.onmousemove = function(e) {
          // 通过事件委托，计算移动的距离
          let left = e.clientX - disX
          let top = e.clientY - disY
          // 边界处理
          if (-left > minDragDomLeft) {
            left = -minDragDomLeft
          } else if (left > maxDragDomLeft) {
            left = maxDragDomLeft
          }
  
          if (-top > minDragDomTop) {
            top = -minDragDomTop
          } else if (top > maxDragDomTop) {
            top = maxDragDomTop
          }
  
          // 移动当前元素
          dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`
        }
  
        document.onmouseup = function(e) {
          e.preventDefault()
          document.onmousemove = null
          document.onmouseup = null
        }
        return false
      }
    }
  })
  