对话框拖拽指令

        Vue.directive('dialogDrag', {
            bind (el, binding, vnode, oldVnode) {
                const dialogHeaderEl = el.querySelector('.el-dialog__header')
                const dragDom = el.querySelector('.el-dialog')
                dialogHeaderEl.style.cursor = 'move'
                // console.log("绑定元素：",el);
                // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
                const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null)

                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

                    // 获取到的值带px 正则匹配替换
                    let styL, styT

                    // 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 (sty.left.includes('%')) {
                        styL = +document.body.clientWidth * (+sty.left.replace(/%/g, '') / 100)
                        styT = +document.body.clientHeight * (+sty.top.replace(/%/g, '') / 100)
                    } else {
                        styL = +sty.left.replace(/px/g, '')
                        styT = +sty.top.replace(/px/g, '')
                    }

                    document.onmousemove = function (e) {
                        // 通过事件委托，计算移动的距离
                        const l = e.clientX - disX
                        const t = e.clientY - disY

                        // 移动当前元素
                        dragDom.style.left = `${l + styL}px`
                        // 判断弹窗位置，防止弹窗头部移出可视区
                        dragDom.style.top = `${(t + styT) < 0 ? 0 : t + styT}px`
                    }

                    document.onmouseup = function (e) {
                        document.onmousemove = null
                        document.onmouseup = null
                    }
                }
            }
        });