效果：

可拖拽弹窗，左右上下拉伸调 双击全屏放大

使用：

引用js，添加v-Drag 指令

// 引用封装好的js
<script src="~/Content/vue/dropDialog.js"></script>

// 添加v-Drag指令
<template>
    <el-dialog v-Drag title="收入明细">
        <el-table :data="DetailData" border max-height="500px">
            <el-table-column prop="Remark" label="备注"></el-table-column>
        </el-table>
    </el-dialog>
</template>

Vue.js：

封装一个指令: v-Drag

//弹窗拖拽 调整弹窗大小 双击放大
Vue.directive('Drag', {
    bind(el, binding, vnode, oldVnode) {
        // 弹框可拉伸最小宽高
        const minWidth = 400
        const minHeight = 300
        // 初始非全屏
        let isFullScreen = false
        // 当前顶部高度
        let nowMarginTop = 0
        // 获取弹框头部（这部分可双击全屏）
        const dialogHeaderEl = el.querySelector('.el-dialog__header')
        // 弹窗
        const dragDom = el.querySelector('.el-dialog')
        // 给弹窗加上overflow auto；不然缩小时框内的标签可能超出dialog；
        dragDom.style.overflow = 'auto'
        // 清除选择头部文字效果
        // dialogHeaderEl.onselectstart = new Function("return false");
        // 头部加上可拖动cursor
        dialogHeaderEl.style.cursor = 'move'
        // 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)
        const moveDown = 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 = `${l + styL}px`
                dragDom.style.top = `${t + styT}px`
                // 将此时的位置传出去
                // binding.value({x:e.pageX,y:e.pageY})
            }
            document.onmouseup = function (e) {
                document.onmousemove = null
                document.onmouseup = null
            }
        }
        dialogHeaderEl.onmousedown = moveDown
        // 当前宽高
        let nowWidth = 0
        // let nowHight = 0
        // 双击头部全屏效果
        dialogHeaderEl.ondblclick = e => {
            if (isFullScreen === false) {
                // nowHight = dragDom.clientHeight
                nowWidth = dragDom.clientWidth
                nowMarginTop = dragDom.style.marginTop
                dragDom.style.left = 0
                dragDom.style.top = 0
                dragDom.style.height = '100VH'
                dragDom.style.width = '100VW'
                dragDom.style.marginTop = 0
                isFullScreen = true
                dialogHeaderEl.style.cursor = 'initial'
                dialogHeaderEl.onmousedown = null
            } else {
                dragDom.style.height = 'auto'
                dragDom.style.width = nowWidth + 'px'
                dragDom.style.marginTop = nowMarginTop
                isFullScreen = false
                dialogHeaderEl.style.cursor = 'move'
                dialogHeaderEl.onmousedown = moveDown
            }
        }
        dragDom.onmousemove = function (e) {
            // let moveE = e
            if (
                e.clientX > dragDom.offsetLeft + dragDom.clientWidth - 10 ||
                dragDom.offsetLeft + 10 > e.clientX
            ) {
                dragDom.style.cursor = 'w-resize'
            } else if (
                el.scrollTop + e.clientY >
                dragDom.offsetTop + dragDom.clientHeight - 10
            ) {
                dragDom.style.cursor = 's-resize'
            } else {
                dragDom.style.cursor = 'default'

                dragDom.onmousedown = null
            }
            dragDom.onmousedown = e => {
                const clientX = e.clientX
                const clientY = e.clientY
                const elW = dragDom.clientWidth
                const elH = dragDom.clientHeight
                const EloffsetLeft = dragDom.offsetLeft
                const EloffsetTop = dragDom.offsetTop
                dragDom.style.userSelect = 'none'
                const ELscrollTop = el.scrollTop
                // 判断点击的位置是不是为头部
                if (
                    clientX > EloffsetLeft &&
                    clientX < EloffsetLeft + elW &&
                    clientY > EloffsetTop &&
                    clientY < EloffsetTop + 100
                ) {
                    // 如果是头部在此就不做任何动作，以上有绑定dialogHeaderEl.onmousedown = moveDown;
                } else {
                    document.onmousemove = function (e) {
                        // 移动时禁用默认事件
                        e.preventDefault()
                        // 左侧鼠标拖拽位置
                        if (clientX > EloffsetLeft && clientX < EloffsetLeft + 10) {
                            // 往左拖拽
                            if (clientX > e.clientX) {
                                dragDom.style.width = elW + (clientX - e.clientX) * 2 + 'px'
                            }
                            // 往右拖拽
                            if (clientX < e.clientX) {
                                if (dragDom.clientWidth < minWidth) {
                                    console.log()
                                } else {
                                    dragDom.style.width = elW - (e.clientX - clientX) * 2 + 'px'
                                }
                            }
                        }
                        // 右侧鼠标拖拽位置
                        if (
                            clientX > EloffsetLeft + elW - 10 &&
                            clientX < EloffsetLeft + elW
                        ) {
                            // 往左拖拽
                            if (clientX > e.clientX) {
                                if (dragDom.clientWidth < minWidth) {
                                    console.log()
                                } else {
                                    dragDom.style.width = elW - (clientX - e.clientX) * 2 + 'px'
                                }
                            }
                            // 往右拖拽
                            if (clientX < e.clientX) {
                                dragDom.style.width = elW + (e.clientX - clientX) * 2 + 'px'
                            }
                        }
                        // 底部鼠标拖拽位置
                        if (
                            ELscrollTop + clientY > EloffsetTop + elH - 20 &&
                            ELscrollTop + clientY < EloffsetTop + elH
                        ) {
                            // 往上拖拽
                            if (clientY > e.clientY) {
                                if (dragDom.clientHeight < minHeight) {
                                    console.log()
                                } else {
                                    dragDom.style.height = elH - (clientY - e.clientY) * 2 + 'px'
                                }
                            }
                            // 往下拖拽
                            if (clientY < e.clientY) {
                                dragDom.style.height = elH + (e.clientY - clientY) * 2 + 'px'
                            }
                        }
                    }
                    // 拉伸结束
                    document.onmouseup = function (e) {
                        document.onmousemove = null

                        document.onmouseup = null
                    }
                }
            }
        }
    }

});