实现在引入vue.js中element-ui的el-dialog弹框拖拽

<el-dialog class="confirm"  v-dialogDrag> </el-dialog>

// v-dialogDrag: 弹窗拖拽
Vue.directive('dialogDrag', {
        bind(el, binding, vnode) {
            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 getStyle = (function() {
                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 dragDomWidth = dragDom.offsetWidth
                const dragDomHeight = dragDom.offsetHeight

                const screenWidth = document.body.clientWidth
                const screenHeight = document.body.clientHeight

                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 = getStyle(dragDom, 'left')
                let styT = getStyle(dragDom, 'top')

                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;`

                    // emit onDrag event
                    vnode.child.$emit('dragDialog')
                }

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

})

如果是使用vue-cli模板,在
main.js中引入该js,使用办法如上