text: import Vue from 'vue';
  
  // v-dialogDrag: 弹窗拖拽属性
  Vue.directive('dialogDrag', {
      bind(el, 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;'
  
          // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
          const sty = (() => {
              if (window.document.currentStyle) {
                  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;
              const screenWidth = document.body.clientWidth; // body当前宽度
              const screenHeight = document.documentElement.clientHeight; // 可见区域高度(应为body高度，可某些环境下无法获取) 
              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');
              let styT = sty(dragDom, 'top');
  
              // 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) {
                  document.onmousemove = null;
                  document.onmouseup = null;
              };
          }
      }
  })
  