在现代 Web 应用中，选中文本后显示相关操作或信息是一种常见的交互模式。本文将详细介绍如何在 Vue 中实现选中文本后弹出弹窗的功能，包括其工作原理、多种实现方式以及实际项目中的应用示例。

一、实现原理

1. 文本选中检测机制

浏览器提供了 Selection API 来检测用户选中的文本内容。我们可以通过监听 mouseup 和 keyup 事件来检测用户是否进行了文本选择操作。

核心 API：

window.getSelection() - 获取当前选中的文本
selection.toString() - 获取选中文本的字符串内容
selection.rangeCount - 获取选中范围的个数
selection.getRangeAt(index) - 获取具体的选区范围

2. 弹窗显示逻辑

当选中文本后，我们需要：

检测是否有文本被选中（排除空选择）
获取选中文本的内容和位置信息
在合适的位置显示弹窗（通常在选中文本附近）
处理弹窗的显示/隐藏状态

二、基础实现方案

方案一：使用原生 JavaScript + Vue 组合

<template><div class="text-container" @mouseup="handleTextSelect" @keyup="handleTextSelect"><p>这是一段可以选中文本的示例内容。当你选中这段文本时，将会显示一个弹窗，展示选中文本的相关信息和操作选项。你可以尝试选中任意文字来体验这个功能。</p><p>Vue.js 是一个用于构建用户界面的渐进式框架。它被设计为可以自底向上逐层应用。Vue 的核心库只关注视图层，不仅易于上手，还便于与第三方库或既有项目整合。</p><!-- 选中文本弹窗 --><div v-if="showPopup" class="text-popup":style="{ left: popupPosition.x + 'px', top: popupPosition.y + 'px' }"ref="popup"><div class="popup-content"><h4>选中文本</h4><p class="selected-text">{{ selectedText }}</p><div class="popup-actions"><button @click="copyText">复制文本</button><button @click="searchText">搜索文本</button><button @click="closePopup">关闭</button></div></div></div></div>
</template><script>
export default {name: 'TextSelectionPopup',data() {return {selectedText: '',showPopup: false,popupPosition: { x: 0, y: 0 },selectionTimeout: null}},methods: {handleTextSelect() {// 使用 setTimeout 确保选择操作完成后再获取选中文本if (this.selectionTimeout) {clearTimeout(this.selectionTimeout)}this.selectionTimeout = setTimeout(() => {const selection = window.getSelection()const selectedContent = selection.toString().trim()if (selectedContent && selectedContent.length > 0) {this.selectedText = selectedContentthis.showPopup = truethis.updatePopupPosition(selection)} else {this.showPopup = false}}, 10)},updatePopupPosition(selection) {if (selection.rangeCount > 0) {const range = selection.getRangeAt(0)const rect = range.getBoundingClientRect()// 计算弹窗位置，避免超出视窗const popupWidth = 250 // 预估弹窗宽度const viewportWidth = window.innerWidthconst viewportHeight = window.innerHeightlet x = rect.left + window.scrollXlet y = rect.bottom + window.scrollY + 5// 水平位置调整if (x + popupWidth > viewportWidth) {x = rect.right + window.scrollX - popupWidth}// 垂直位置调整if (y + 200 > viewportHeight + window.scrollY) {y = rect.top + window.scrollY - 200}this.popupPosition = { x, y }}},closePopup() {this.showPopup = falsethis.clearSelection()},clearSelection() {const selection = window.getSelection()selection.removeAllRanges()},copyText() {navigator.clipboard.writeText(this.selectedText).then(() => {alert('文本已复制到剪贴板')this.closePopup()}).catch(() => {// 降级方案const textArea = document.createElement('textarea')textArea.value = this.selectedTextdocument.body.appendChild(textArea)textArea.select()document.execCommand('copy')document.body.removeChild(textArea)alert('文本已复制到剪贴板')this.closePopup()})},searchText() {const searchUrl = `https://www.google.com/search?q=${encodeURIComponent(this.selectedText)}`window.open(searchUrl, '_blank')this.closePopup()}},mounted() {// 监听点击其他地方关闭弹窗document.addEventListener('click', (e) => {if (this.showPopup && !this.$refs.popup?.contains(e.target)) {this.closePopup()}})},beforeUnmount() {if (this.selectionTimeout) {clearTimeout(this.selectionTimeout)}document.removeEventListener('click', this.closePopup)}
}
</script><style scoped>
.text-container {max-width: 800px;margin: 0 auto;padding: 20px;line-height: 1.6;font-size: 16px;
}.text-popup {position: fixed;z-index: 1000;background: white;border: 1px solid #ddd;border-radius: 8px;box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);min-width: 200px;max-width: 300px;animation: popupShow 0.2s ease-out;
}@keyframes popupShow {from {opacity: 0;transform: translateY(-10px);}to {opacity: 1;transform: translateY(0);}
}.popup-content {padding: 12px;
}.popup-content h4 {margin: 0 0 8px 0;font-size: 14px;color: #333;
}.selected-text {margin: 8px 0;padding: 8px;background: #f5f5f5;border-radius: 4px;font-size: 13px;word-break: break-word;color: #333;
}.popup-actions {display: flex;gap: 8px;margin-top: 12px;
}.popup-actions button {flex: 1;padding: 6px 8px;border: 1px solid #ddd;border-radius: 4px;background: white;cursor: pointer;font-size: 12px;transition: all 0.2s;
}.popup-actions button:hover {background: #f0f0f0;border-color: #999;
}.popup-actions button:first-child {background: #007bff;color: white;border-color: #007bff;
}.popup-actions button:first-child:hover {background: #0056b3;border-color: #0056b3;
}
</style>

方案解析

事件监听：通过 @mouseup 和 @keyup 事件监听用户的文本选择操作
选择检测：使用 window.getSelection() 获取用户选中的文本
位置计算：通过 getBoundingClientRect() 获取选中文本的位置，智能计算弹窗显示位置
弹窗控制：使用 Vue 的响应式数据控制弹窗的显示/隐藏
功能扩展：实现了复制文本、搜索文本等实用功能

三、进阶实现方案

方案二：使用自定义指令实现

创建一个可复用的 Vue 自定义指令，让任何元素都具备选中文本弹窗功能。

// directives/textSelectionPopup.js
export default {mounted(el, binding) {let showPopup = falselet selectedText = ''let popupTimeout = nullconst showSelectionPopup = () => {if (popupTimeout) {clearTimeout(popupTimeout)}popupTimeout = setTimeout(() => {const selection = window.getSelection()const content = selection.toString().trim()if (content && content.length > 0) {selectedText = contentshowPopup = trueupdatePopupPosition(selection, el)binding.value?.onShow?.({ text: selectedText, element: el })} else {hidePopup()}}, 10)}const hidePopup = () => {showPopup = falseselectedText = ''binding.value?.onHide?.()}const updatePopupPosition = (selection, containerEl) => {if (selection.rangeCount > 0) {const range = selection.getRangeAt(0)const rect = range.getBoundingClientRect()const containerRect = containerEl.getBoundingClientRect()// 这里可以 emit 位置信息给父组件const popupData = {x: rect.left,y: rect.bottom + 5,width: rect.width,height: rect.height,text: selectedText}binding.value?.onPositionChange?.(popupData)}}// 监听容器内的选择事件el.addEventListener('mouseup', showSelectionPopup)el.addEventListener('keyup', showSelectionPopup)// 全局点击关闭const handleClickOutside = (e) => {if (showPopup && !el.contains(e.target)) {// 检查点击的是否是弹窗本身（需要通过 binding 传递弹窗引用）hidePopup()}}// 保存清理函数el._textSelectionPopup = {showSelectionPopup,hidePopup,handleClickOutside,cleanup: () => {el.removeEventListener('mouseup', showSelectionPopup)el.removeEventListener('keyup', showSelectionPopup)document.removeEventListener('click', handleClickOutside)if (popupTimeout) {clearTimeout(popupTimeout)}}}document.addEventListener('click', handleClickOutside)},unmounted(el) {if (el._textSelectionPopup) {el._textSelectionPopup.cleanup()}}
}

在 main.js 中注册指令：

import { createApp } from 'vue'
import App from './App.vue'
import textSelectionPopup from './directives/textSelectionPopup'const app = createApp(App)
app.directive('text-selection-popup', textSelectionPopup)
app.mount('#app')

使用示例：

<template><div v-text-selection-popup="{onShow: handlePopupShow,onHide: handlePopupHide,onPositionChange: handlePositionChange}"class="content-area"><h2>使用自定义指令的文本选择区域</h2><p>这个区域使用了自定义指令来实现文本选择弹窗功能。指令封装了所有的选择检测和弹窗逻辑，使得组件代码更加简洁。</p><p>你可以选中任意文本，系统会自动检测并触发相应的回调函数。这种方式更加灵活，可以在不同的组件中复用相同的逻辑。</p></div><!-- 弹窗组件（可以是全局组件） --><TextSelectionPopupv-if="popupVisible":text="selectedText":position="popupPosition"@close="closePopup"@copy="copyText"@search="searchText"/>
</template><script>
import TextSelectionPopup from './components/TextSelectionPopup.vue'export default {components: {TextSelectionPopup},data() {return {popupVisible: false,selectedText: '',popupPosition: { x: 0, y: 0 }}},methods: {handlePopupShow(data) {this.selectedText = data.textthis.popupVisible = trueconsole.log('弹窗显示', data)},handlePopupHide() {this.popupVisible = false},handlePositionChange(position) {this.popupPosition = { x: position.x, y: position.y + 20 }},closePopup() {this.popupVisible = false},copyText() {// 复制文本逻辑console.log('复制文本:', this.selectedText)},searchText() {// 搜索文本逻辑console.log('搜索文本:', this.selectedText)}}
}
</script>

方案三：使用 Composition API 封装

对于 Vue 3 项目，我们可以使用 Composition API 创建一个可复用的 composable 函数。

// composables/useTextSelectionPopup.js
import { ref, onMounted, onUnmounted } from 'vue'export function useTextSelectionPopup(options = {}) {const {onTextSelected = () => {},onPopupClose = () => {},popupComponent: PopupComponent = null,popupProps = {}} = optionsconst selectedText = ref('')const showPopup = ref(false)const popupPosition = ref({ x: 0, y: 0 })const selectionTimeout = ref(null)const handleTextSelect = () => {if (selectionTimeout.value) {clearTimeout(selectionTimeout.value)}selectionTimeout.value = setTimeout(() => {const selection = window.getSelection()const content = selection.toString().trim()if (content && content.length > 0) {selectedText.value = contentshowPopup.value = trueupdatePopupPosition(selection)onTextSelected({ text: content, element: document.activeElement })} else {hidePopup()}}, 10)}const updatePopupPosition = (selection) => {if (selection.rangeCount > 0) {const range = selection.getRangeAt(0)const rect = range.getBoundingClientRect()popupPosition.value = {x: rect.left,y: rect.bottom + 5}}}const hidePopup = () => {showPopup.value = falseselectedText.value = ''onPopupClose()}const clearSelection = () => {const selection = window.getSelection()selection.removeAllRanges()}const handleClickOutside = (event, popupRef) => {if (showPopup.value && popupRef && !popupRef.contains(event.target)) {hidePopup()}}onMounted(() => {document.addEventListener('mouseup', handleTextSelect)document.addEventListener('keyup', handleTextSelect)})onUnmounted(() => {if (selectionTimeout.value) {clearTimeout(selectionTimeout.value)}document.removeEventListener('mouseup', handleTextSelect)document.removeEventListener('keyup', handleTextSelect)})return {selectedText,showPopup,popupPosition,hidePopup,clearSelection,handleClickOutside,handleTextSelect}
}

使用 Composition API 的组件示例：

<template><div class="content-area"><h2>使用 Composition API 的文本选择</h2><p>这个示例展示了如何使用 Vue 3 的 Composition API 来封装文本选择弹窗功能。通过创建可复用的 composable 函数，我们可以在多个组件中轻松使用相同的功能。</p><div class="text-block"><p>Vue 3 的 Composition API 提供了更灵活的逻辑复用方式。</p><p>你可以选中这些文字来测试文本选择弹窗功能。</p></div><!-- 如果有弹窗组件 --><Teleport to="body"><div v-if="showPopup" class="global-popup":style="{ left: popupPosition.x + 'px', top: popupPosition.y + 'px' }"ref="popupRef"><div class="popup-content"><h4>选中的文本</h4><p>{{ selectedText }}</p><button @click="hidePopup">关闭</button></div></div></Teleport></div>
</template><script setup>
import { ref } from 'vue'
import { useTextSelectionPopup } from '@/composables/useTextSelectionPopup'const popupRef = ref(null)const {selectedText,showPopup,popupPosition,hidePopup,handleTextSelect
} = useTextSelectionPopup({onTextSelected: ({ text }) => {console.log('文本已选择:', text)},onPopupClose: () => {console.log('弹窗已关闭')}
})// 监听全局点击事件
const handleGlobalClick = (event) => {if (showPopup && popupRef.value && !popupRef.value.contains(event.target)) {hidePopup()}
}// 在 setup 中添加全局事件监听
import { onMounted, onUnmounted } from 'vue'onMounted(() => {document.addEventListener('click', handleGlobalClick)
})onUnmounted(() => {document.removeEventListener('click', handleGlobalClick)
})
</script>