1.在已经写好的对话框添加属性

:close-on-click-modal="false"//禁止点击遮罩层关闭弹出层
 v-dialogDrag//指令就可以实现弹窗的全屏和拉伸了
 //如果是form表单，不要将提交等按钮放置el-form-item，以免在上下拉伸时被隐藏

下面是添加的位置，可以模仿一下

<el-dialog title="详情信息" :close-on-click-modal="false" v-dialogDrag :visible.sync="dialogVisible" class="view_details1 view_details" append-to-body>
        <IndicatorsDetails :currentVal="currentVal" :Data="StatisticsChange">
        </IndicatorsDetails>
      </el-dialog>

2.准备好实现功能的js文件----------drag.js

// v-dialogDrag: 弹窗拖拽+水平方向伸缩
import Vue from 'vue';
Vue.directive('dialogDrag', {
    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
                    }
                }
            }
        }
    }
})

3.将写好的drag.js文件引入main.js

注意地址是可以变的，根据自己的地址进行变化

import './utils/drag'