Vue3 Teleport 深度解析：实现跨组件DOM传送的完整指南

北辰alk
103 阅读12分钟

摘要

Teleport 是 Vue3 引入的一个革命性特性，它允许我们将组件模板的一部分"传送"到 DOM 中的其他位置，而不会破坏组件的逻辑层次结构。本文将深入探讨 Teleport 的工作原理、使用场景、高级技巧，通过详细的代码示例、执行流程分析和最佳实践，帮助你彻底掌握这一强大的特性。

一、 什么是 Teleport？为什么需要它？

1.1 传统模态框的问题

在 Vue2 中，创建模态框、通知框等全局组件时，我们经常遇到这样的问题：

<!-- 传统模态框组件的问题 -->
<template>
  <div>
    <!-- 页面主要内容 -->
    <header>...</header>
    <main>...</main>
    <footer>...</footer>
    
    <!-- 模态框 - 在DOM结构中位置不对 -->
    <div v-if="showModal" class="modal-overlay">
      <div class="modal-content">
        <h2>模态框标题</h2>
        <p>模态框内容...</p>
      </div>
    </div>
  </div>
</template>

传统方式的问题：

  • z-index 问题：模态框可能被父元素的样式影响
  • 布局限制：受到父容器 overflow: hidden 的影响
  • 可访问性：屏幕阅读器可能无法正确识别模态框
  • 代码组织：逻辑相关的代码分散在不同位置

1.2 Teleport 的解决方案

Teleport 提供了一种声明式的方式，将模板内容渲染到 DOM 中的指定位置：

<template>
  <div>
    <!-- 页面主要内容 -->
    <header>...</header>
    <main>...</main>
    <footer>...</footer>
    
    <!-- 使用 Teleport 将模态框传送到 body -->
    <Teleport to="body">
      <div v-if="showModal" class="modal-overlay">
        <div class="modal-content">
          <h2>模态框标题</h2>
          <p>模态框内容...</p>
        </div>
      </div>
    </Teleport>
  </div>
</template>

二、 Teleport 核心概念与基本用法

2.1 Teleport 的基本语法

<Teleport to="目标选择器">
  <!-- 要传送的内容 -->
  任何模板内容或组件
</Teleport>

2.2 Teleport 的工作原理

流程图：Teleport 完整工作流程

flowchart TD
    A[Vue组件渲染] --> B[解析Teleport组件]
    B --> C[在组件位置创建注释节点]
    C --> D[查找目标容器]
    D --> E{目标容器存在?}
    E -- 是 --> F[在目标位置创建真实DOM]
    E -- 否 --> G[控制台警告<br>在原位置渲染]
    F --> H[建立响应式连接]
    H --> I[内容保持响应式]
    
    I --> J[组件数据更新]
    J --> K[更新传送的内容]
    K --> L[组件销毁]
    L --> M[清理传送的DOM]

2.3 基础示例：简单的模态框

<template>
  <div class="teleport-basic-demo">
    <h2>Teleport 基础示例</h2>
    <button @click="showModal = true" class="btn-primary">
      打开模态框
    </button>

    <!-- 使用 Teleport 将模态框传送到 body -->
    <Teleport to="body">
      <div v-if="showModal" class="modal-overlay" @click.self="closeModal">
        <div class="modal-content">
          <div class="modal-header">
            <h3>Teleport 模态框</h3>
            <button @click="closeModal" class="close-btn">&times;</button>
          </div>
          <div class="modal-body">
            <p>这个模态框是通过 Teleport 传送到 body 元素的！</p>
            <p>当前计数: {{ count }}</p>
            <button @click="increment" class="btn-secondary">增加计数</button>
          </div>
          <div class="modal-footer">
            <button @click="closeModal" class="btn-primary">关闭</button>
          </div>
        </div>
      </div>
    </Teleport>

    <div class="demo-info">
      <p>检查 Elements 面板，可以看到模态框被渲染在 body 的直接子元素位置，</p>
      <p>而不是在这个组件的 DOM 结构内部。</p>
    </div>
  </div>
</template>

<script setup>
import { ref } from 'vue'

const showModal = ref(false)
const count = ref(0)

const closeModal = () => {
  showModal.value = false
}

const increment = () => {
  count.value++
}
</script>

<style scoped>
.teleport-basic-demo {
  padding: 20px;
  max-width: 800px;
  margin: 0 auto;
  font-family: Arial, sans-serif;
}

.btn-primary {
  background: #42b883;
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 16px;
}

.btn-primary:hover {
  background: #369870;
}

.btn-secondary {
  background: #3498db;
  color: white;
  border: none;
  padding: 8px 16px;
  border-radius: 4px;
  cursor: pointer;
}

.demo-info {
  margin-top: 20px;
  padding: 15px;
  background: #f5f5f5;
  border-radius: 8px;
  font-size: 14px;
  color: #666;
}

/* 模态框样式 - 这些样式是全局的，因为模态框被传送到 body */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal-content {
  background: white;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
}

.modal-header {
  padding: 20px;
  border-bottom: 1px solid #e0e0e0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h3 {
  margin: 0;
  color: #2c3e50;
}

.close-btn {
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: #7f8c8d;
  padding: 0;
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.close-btn:hover {
  color: #e74c3c;
}

.modal-body {
  padding: 20px;
}

.modal-footer {
  padding: 20px;
  border-top: 1px solid #e0e0e0;
  text-align: right;
}
</style>

三、 Teleport 的高级用法

3.1 条件性 Teleport

<template>
  <div class="conditional-teleport-demo">
    <h2>条件性 Teleport</h2>
    
    <div class="controls">
      <label>
        <input type="checkbox" v-model="useTeleport"> 
        使用 Teleport
      </label>
      <label>
        <input type="checkbox" v-model="showContent"> 
        显示内容
      </label>
      <select v-model="target">
        <option value="body">body</option>
        <option value="#teleport-target-1">目标1</option>
        <option value="#teleport-target-2">目标2</option>
      </select>
    </div>

    <!-- 条件性使用 Teleport -->
    <template v-if="useTeleport">
      <Teleport :to="target" :disabled="!showContent">
        <DynamicContent :message="currentMessage" />
      </Teleport>
    </template>
    <template v-else>
      <DynamicContent v-if="showContent" :message="currentMessage" />
    </template>

    <!-- 多个传送目标 -->
    <div class="targets">
      <div id="teleport-target-1" class="target-box">
        <h4>传送目标 1</h4>
      </div>
      <div id="teleport-target-2" class="target-box">
        <h4>传送目标 2</h4>
      </div>
    </div>

    <button @click="changeMessage" class="btn-primary">
      改变消息
    </button>
  </div>
</template>

<script setup>
import { ref, computed } from 'vue'
import DynamicContent from './DynamicContent.vue'

const useTeleport = ref(true)
const showContent = ref(true)
const target = ref('body')
const messageCount = ref(0)

const currentMessage = computed(() => 
  `动态消息 #${messageCount.value} - 目标: ${target.value}`
)

const changeMessage = () => {
  messageCount.value++
}
</script>

<style scoped>
.conditional-teleport-demo {
  padding: 20px;
  max-width: 1000px;
  margin: 0 auto;
}

.controls {
  margin: 20px 0;
  padding: 15px;
  background: #f8f9fa;
  border-radius: 8px;
  display: flex;
  gap: 20px;
  align-items: center;
}

.controls label {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.controls select {
  padding: 5px 10px;
  border: 1px solid #ddd;
  border-radius: 4px;
}

.targets {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin: 20px 0;
}

.target-box {
  border: 2px dashed #42b883;
  border-radius: 8px;
  padding: 20px;
  min-height: 100px;
  background: #f8fff8;
}

.target-box h4 {
  margin: 0 0 10px 0;
  color: #42b883;
}
</style>

DynamicContent.vue

<template>
  <div class="dynamic-content">
    <h3>动态内容组件</h3>
    <p>{{ props.message }}</p>
    <p>组件实例: {{ instanceId }}</p>
    <p>当前时间: {{ currentTime }}</p>
    <button @click="updateTime" class="btn-secondary">
      更新时间
    </button>
  </div>
</template>

<script setup>
import { ref, onMounted, onUnmounted } from 'vue'

const props = defineProps({
  message: {
    type: String,
    default: '默认消息'
  }
})

const instanceId = ref(Math.random().toString(36).substr(2, 9))
const currentTime = ref(new Date().toLocaleTimeString())

const updateTime = () => {
  currentTime.value = new Date().toLocaleTimeString()
}

onMounted(() => {
  console.log(`DynamicContent 组件已挂载 - ID: ${instanceId.value}`)
})

onUnmounted(() => {
  console.log(`DynamicContent 组件已卸载 - ID: ${instanceId.value}`)
})
</script>

<style scoped>
.dynamic-content {
  padding: 15px;
  border: 2px solid #3498db;
  border-radius: 8px;
  background: #e3f2fd;
  margin: 10px 0;
}

.dynamic-content h3 {
  margin: 0 0 10px 0;
  color: #2c3e50;
}
</style>

3.2 多个 Teleport 到同一目标

<template>
  <div class="multiple-teleport-demo">
    <h2>多个 Teleport 到同一目标</h2>
    
    <div class="notification-controls">
      <button @click="addSuccessNotification" class="btn-success">
        成功通知
      </button>
      <button @click="addWarningNotification" class="btn-warning">
        警告通知
      </button>
      <button @click="addErrorNotification" class="btn-error">
        错误通知
      </button>
      <button @click="clearNotifications" class="btn-secondary">
        清空所有
      </button>
    </div>

    <!-- 多个 Teleport 指向同一个目标 -->
    <Teleport to="#notifications-container">
      <div 
        v-for="notification in notifications" 
        :key="notification.id"
        :class="['notification', `notification-${notification.type}`]"
      >
        <span class="notification-icon">{{ getIcon(notification.type) }}</span>
        <div class="notification-content">
          <h4>{{ notification.title }}</h4>
          <p>{{ notification.message }}</p>
        </div>
        <button 
          @click="removeNotification(notification.id)" 
          class="notification-close"
        >
          &times;
        </button>
      </div>
    </Teleport>

    <!-- 通知容器（在实际项目中可能放在 App.vue 中） -->
    <div id="notifications-container" class="notifications-container"></div>

    <div class="demo-info">
      <p>所有通知都被传送到同一个容器中，它们会按照添加顺序显示。</p>
      <p>即使有多个组件同时传送通知，它们也会在同一个位置协调显示。</p>
    </div>
  </div>
</template>

<script setup>
import { ref } from 'vue'

const notifications = ref([])
let nextId = 1

const addSuccessNotification = () => {
  notifications.value.push({
    id: nextId++,
    type: 'success',
    title: '操作成功',
    message: `您的操作已经成功完成 (#${nextId - 1})`
  })
}

const addWarningNotification = () => {
  notifications.value.push({
    id: nextId++,
    type: 'warning',
    title: '警告提示',
    message: `请注意当前操作的风险 (#${nextId - 1})`
  })
}

const addErrorNotification = () => {
  notifications.value.push({
    id: nextId++,
    type: 'error',
    title: '发生错误',
    message: `操作过程中出现了问题 (#${nextId - 1})`
  })
}

const removeNotification = (id) => {
  notifications.value = notifications.value.filter(n => n.id !== id)
}

const clearNotifications = () => {
  notifications.value = []
}

const getIcon = (type) => {
  const icons = {
    success: '✅',
    warning: '⚠️',
    error: '❌'
  }
  return icons[type] || '💡'
}
</script>

<style scoped>
.multiple-teleport-demo {
  padding: 20px;
  max-width: 800px;
  margin: 0 auto;
}

.notification-controls {
  margin: 20px 0;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.btn-success { background: #27ae60; }
.btn-warning { background: #f39c12; }
.btn-error { background: #e74c3c; }
.btn-secondary { background: #7f8c8d; }

.btn-success, .btn-warning, .btn-error, .btn-secondary {
  color: white;
  border: none;
  padding: 10px 16px;
  border-radius: 4px;
  cursor: pointer;
}

.btn-success:hover { background: #229954; }
.btn-warning:hover { background: #e67e22; }
.btn-error:hover { background: #c0392b; }
.btn-secondary:hover { background: #6c7a7d; }

/* 通知容器样式 */
.notifications-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1000;
  max-width: 400px;
}

/* 通知项样式 */
.notification {
  display: flex;
  align-items: flex-start;
  padding: 15px;
  margin-bottom: 10px;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  animation: slideIn 0.3s ease-out;
  min-width: 300px;
}

.notification-success {
  background: #d4edda;
  border: 1px solid #c3e6cb;
  color: #155724;
}

.notification-warning {
  background: #fff3cd;
  border: 1px solid #ffeaa7;
  color: #856404;
}

.notification-error {
  background: #f8d7da;
  border: 1px solid #f5c6cb;
  color: #721c24;
}

.notification-icon {
  font-size: 20px;
  margin-right: 12px;
  flex-shrink: 0;
}

.notification-content {
  flex: 1;
}

.notification-content h4 {
  margin: 0 0 5px 0;
  font-size: 16px;
}

.notification-content p {
  margin: 0;
  font-size: 14px;
  opacity: 0.9;
}

.notification-close {
  background: none;
  border: none;
  font-size: 18px;
  cursor: pointer;
  opacity: 0.7;
  padding: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-left: 10px;
}

.notification-close:hover {
  opacity: 1;
}

@keyframes slideIn {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

.demo-info {
  margin-top: 30px;
  padding: 15px;
  background: #f5f5f5;
  border-radius: 8px;
  font-size: 14px;
  color: #666;
}
</style>

四、 Teleport 在实际项目中的应用场景

4.1 完整的模态框系统

<template>
  <div class="modal-system-demo">
    <h2>模态框系统</h2>
    
    <div class="modal-buttons">
      <button @click="openModal('login')" class="btn-primary">
        登录模态框
      </button>
      <button @click="openModal('confirm')" class="btn-warning">
        确认对话框
      </button>
      <button @click="openModal('settings')" class="btn-secondary">
        设置模态框
      </button>
    </div>

    <!-- 模态框传送系统 -->
    <Teleport to="#modal-container">
      <!-- 登录模态框 -->
      <LoginModal 
        v-if="activeModal === 'login'"
        @close="closeModal"
        @login="handleLogin"
      />
      
      <!-- 确认对话框 -->
      <ConfirmModal
        v-if="activeModal === 'confirm'"
        @close="closeModal"
        @confirm="handleConfirm"
        title="确认操作"
        message="您确定要执行此操作吗？此操作不可撤销。"
      />
      
      <!-- 设置模态框 -->
      <SettingsModal
        v-if="activeModal === 'settings'"
        @close="closeModal"
        @save="handleSaveSettings"
      />
    </Teleport>

    <!-- 全局模态框容器（通常在 App.vue 中定义） -->
    <div id="modal-container"></div>

    <div class="user-info" v-if="user">
      <h3>用户信息</h3>
      <p>用户名: {{ user.username }}</p>
      <p>邮箱: {{ user.email }}</p>
    </div>
  </div>
</template>

<script setup>
import { ref } from 'vue'
import LoginModal from './modals/LoginModal.vue'
import ConfirmModal from './modals/ConfirmModal.vue'
import SettingsModal from './modals/SettingsModal.vue'

const activeModal = ref(null)
const user = ref(null)

const openModal = (modalType) => {
  activeModal.value = modalType
}

const closeModal = () => {
  activeModal.value = null
}

const handleLogin = (userData) => {
  user.value = userData
  closeModal()
}

const handleConfirm = () => {
  console.log('用户确认了操作')
  closeModal()
}

const handleSaveSettings = (settings) => {
  console.log('保存设置:', settings)
  closeModal()
}
</script>

<style scoped>
.modal-system-demo {
  padding: 20px;
  max-width: 800px;
  margin: 0 auto;
}

.modal-buttons {
  display: flex;
  gap: 15px;
  margin: 20px 0;
  flex-wrap: wrap;
}

.user-info {
  margin-top: 30px;
  padding: 20px;
  background: #f8f9fa;
  border-radius: 8px;
  border: 1px solid #e9ecef;
}

.user-info h3 {
  margin: 0 0 15px 0;
  color: #2c3e50;
}
</style>

LoginModal.vue

<template>
  <div class="modal-overlay" @click.self="$emit('close')">
    <div class="modal-content modal-medium">
      <div class="modal-header">
        <h3>用户登录</h3>
        <button @click="$emit('close')" class="close-btn">&times;</button>
      </div>
      
      <div class="modal-body">
        <form @submit.prevent="handleSubmit" class="login-form">
          <div class="form-group">
            <label for="username">用户名:</label>
            <input
              id="username"
              v-model="form.username"
              type="text"
              required
              placeholder="请输入用户名"
            />
          </div>
          
          <div class="form-group">
            <label for="password">密码:</label>
            <input
              id="password"
              v-model="form.password"
              type="password"
              required
              placeholder="请输入密码"
            />
          </div>
          
          <div class="form-options">
            <label class="checkbox-label">
              <input type="checkbox" v-model="form.remember">
              记住我
            </label>
            <a href="#" class="forgot-link">忘记密码？</a>
          </div>
        </form>
      </div>
      
      <div class="modal-footer">
        <button @click="$emit('close')" class="btn-secondary">
          取消
        </button>
        <button @click="handleSubmit" class="btn-primary" :disabled="!formValid">
          登录
        </button>
      </div>
    </div>
  </div>
</template>

<script setup>
import { ref, computed, reactive } from 'vue'

const emit = defineEmits(['close', 'login'])

const form = reactive({
  username: '',
  password: '',
  remember: false
})

const formValid = computed(() => {
  return form.username.trim() && form.password.trim()
})

const handleSubmit = () => {
  if (formValid.value) {
    emit('login', {
      username: form.username,
      email: `${form.username}@example.com`,
      loginTime: new Date().toLocaleString()
    })
  }
}
</script>

<style scoped>
.modal-medium {
  max-width: 400px;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
}

.form-group label {
  margin-bottom: 8px;
  font-weight: 600;
  color: #2c3e50;
}

.form-group input {
  padding: 10px 12px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 14px;
  transition: border-color 0.3s;
}

.form-group input:focus {
  outline: none;
  border-color: #42b883;
  box-shadow: 0 0 0 2px rgba(66, 184, 131, 0.2);
}

.form-options {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-size: 14px;
}

.forgot-link {
  color: #42b883;
  text-decoration: none;
  font-size: 14px;
}

.forgot-link:hover {
  text-decoration: underline;
}
</style>

4.2 工具提示系统

<template>
  <div class="tooltip-system-demo">
    <h2>工具提示系统</h2>
    
    <div class="tooltip-demo-area">
      <button 
        v-for="item in tooltipItems" 
        :key="item.id"
        class="demo-btn"
        @mouseenter="showTooltip(item)"
        @mouseleave="hideTooltip"
        @focus="showTooltip(item)"
        @blur="hideTooltip"
      >
        {{ item.label }}
      </button>
    </div>

    <!-- 工具提示传送 -->
    <Teleport to="body">
      <div 
        v-if="activeTooltip" 
        class="tooltip"
        :style="tooltipStyle"
        ref="tooltipElement"
      >
        <div class="tooltip-content">
          <h4>{{ activeTooltip.title }}</h4>
          <p>{{ activeTooltip.content }}</p>
        </div>
        <div class="tooltip-arrow"></div>
      </div>
    </Teleport>

    <div class="demo-info">
      <p>工具提示通过 Teleport 传送到 body，确保它们显示在所有内容之上，</p>
      <p>并且不受父容器样式的影响。</p>
    </div>
  </div>
</template>

<script setup>
import { ref, reactive, onMounted, onUnmounted } from 'vue'

const activeTooltip = ref(null)
const tooltipElement = ref(null)
const tooltipStyle = reactive({
  position: 'fixed',
  top: '0',
  left: '0',
  opacity: 0
})

const tooltipItems = [
  {
    id: 1,
    label: '保存',
    title: '保存文档',
    content: '将当前文档保存到您的设备'
  },
  {
    id: 2,
    label: '设置',
    title: '系统设置',
    content: '配置应用程序的首选项和选项'
  },
  {
    id: 3,
    label: '帮助',
    title: '帮助文档',
    content: '访问完整的用户手册和教程'
  },
  {
    id: 4,
    label: '导出',
    title: '导出数据',
    content: '将数据导出为各种格式（PDF、Excel、CSV）'
  }
]

let hoverTimeout = null

const showTooltip = (item) => {
  clearTimeout(hoverTimeout)
  hoverTimeout = setTimeout(() => {
    activeTooltip.value = item
    updateTooltipPosition()
  }, 300)
}

const hideTooltip = () => {
  clearTimeout(hoverTimeout)
  activeTooltip.value = null
}

const updateTooltipPosition = () => {
  if (!activeTooltip.value) return
  
  nextTick(() => {
    const triggerElement = event?.target
    if (!triggerElement || !tooltipElement.value) return
    
    const rect = triggerElement.getBoundingClientRect()
    const tooltipRect = tooltipElement.value.getBoundingClientRect()
    
    // 计算位置（在触发元素上方）
    let top = rect.top - tooltipRect.height - 10
    let left = rect.left + (rect.width - tooltipRect.width) / 2
    
    // 边界检查
    if (top < 10) {
      top = rect.bottom + 10 // 显示在下方
    }
    
    if (left < 10) {
      left = 10
    } else if (left + tooltipRect.width > window.innerWidth - 10) {
      left = window.innerWidth - tooltipRect.width - 10
    }
    
    tooltipStyle.top = `${top}px`
    tooltipStyle.left = `${left}px`
    tooltipStyle.opacity = 1
  })
}

// 监听窗口变化更新位置
onMounted(() => {
  window.addEventListener('scroll', updateTooltipPosition)
  window.addEventListener('resize', updateTooltipPosition)
})

onUnmounted(() => {
  window.removeEventListener('scroll', updateTooltipPosition)
  window.removeEventListener('resize', updateTooltipPosition)
  clearTimeout(hoverTimeout)
})
</script>

<style scoped>
.tooltip-system-demo {
  padding: 40px 20px;
  max-width: 800px;
  margin: 0 auto;
}

.tooltip-demo-area {
  display: flex;
  gap: 15px;
  flex-wrap: wrap;
  justify-content: center;
  margin: 30px 0;
}

.demo-btn {
  padding: 12px 24px;
  background: #3498db;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 16px;
  transition: background 0.3s;
}

.demo-btn:hover {
  background: #2980b9;
}

/* 工具提示样式 */
.tooltip {
  position: fixed;
  z-index: 10000;
  background: #2c3e50;
  color: white;
  padding: 0;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  max-width: 300px;
  transition: opacity 0.2s;
  pointer-events: none;
}

.tooltip-content {
  padding: 15px;
}

.tooltip-content h4 {
  margin: 0 0 8px 0;
  font-size: 14px;
  color: #42b883;
}

.tooltip-content p {
  margin: 0;
  font-size: 13px;
  line-height: 1.4;
  opacity: 0.9;
}

.tooltip-arrow {
  position: absolute;
  width: 0;
  height: 0;
  border-left: 6px solid transparent;
  border-right: 6px solid transparent;
  border-top: 6px solid #2c3e50;
  bottom: -6px;
  left: 50%;
  transform: translateX(-50%);
}

.tooltip[style*="top: calc"] .tooltip-arrow {
  border-top-color: transparent;
  border-bottom: 6px solid #2c3e50;
  top: -6px;
  bottom: auto;
}
</style>

五、 Teleport 的高级特性与最佳实践

5.1 禁用 Teleport

<template>
  <div class="disable-teleport-demo">
    <h2>禁用 Teleport</h2>
    
    <label class="toggle-label">
      <input type="checkbox" v-model="disableTeleport">
      禁用 Teleport（内容将在原地渲染）
    </label>

    <div class="demo-container">
      <Teleport to="body" :disabled="disableTeleport">
        <div class="teleport-content">
          <h3>可传送的内容</h3>
          <p>这个内容可以通过 Teleport 传送到 body</p>
          <p v-if="disableTeleport" class="warning">
            ⚠️ Teleport 已被禁用，内容在当前位置渲染
          </p>
          <p v-else class="success">
            ✅ Teleport 已启用，内容被传送到 body
          </p>
        </div>
      </Teleport>
    </div>

    <div class="position-info">
      <h4>当前位置 DOM 结构：</h4>
      <pre><code>{{ currentDOMStructure }}</code></pre>
    </div>
  </div>
</template>

<script setup>
import { ref, computed } from 'vue'

const disableTeleport = ref(false)

const currentDOMStructure = computed(() => {
  return disableTeleport.value 
    ? `
<div class="demo-container">
  <div class="teleport-content">
    <h3>可传送的内容</h3>
    <p>这个内容可以通过 Teleport 传送到 body</p>
    <p class="warning">⚠️ Teleport 已被禁用...</p>
  </div>
</div>
    `
    : `
<div class="demo-container">
  <!-- teleport content is moved to body -->
</div>

<!-- In body -->
<div class="teleport-content">
  <h3>可传送的内容</h3>
  <p>这个内容可以通过 Teleport 传送到 body</p>
  <p class="success">✅ Teleport 已启用...</p>
</div>
    `
})
</script>

<style scoped>
.disable-teleport-demo {
  padding: 20px;
  max-width: 800px;
  margin: 0 auto;
}

.toggle-label {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 20px 0;
  padding: 15px;
  background: #f8f9fa;
  border-radius: 8px;
  cursor: pointer;
}

.demo-container {
  border: 2px dashed #e0e0e0;
  border-radius: 8px;
  padding: 20px;
  margin: 20px 0;
  min-height: 100px;
  background: #fafafa;
}

.teleport-content {
  padding: 20px;
  border: 2px solid #42b883;
  border-radius: 8px;
  background: #f8fff8;
}

.warning {
  color: #e67e22;
  font-weight: bold;
}

.success {
  color: #27ae60;
  font-weight: bold;
}

.position-info {
  margin-top: 30px;
  padding: 15px;
  background: #2c3e50;
  border-radius: 8px;
  color: white;
}

.position-info h4 {
  margin: 0 0 10px 0;
  color: #42b883;
}

.position-info pre {
  margin: 0;
  background: #34495e;
  padding: 15px;
  border-radius: 4px;
  overflow-x: auto;
  font-size: 12px;
  line-height: 1.4;
}

.position-info code {
  color: #ecf0f1;
}
</style>

5.2 动态目标选择器

<template>
  <div class="dynamic-target-demo">
    <h2>动态目标选择器</h2>
    
    <div class="controls">
      <div class="target-selector">
        <label>选择传送目标:</label>
        <select v-model="selectedTarget">
          <option 
            v-for="target in availableTargets" 
            :key="target.id"
            :value="target.selector"
          >
            {{ target.name }}
          </option>
        </select>
      </div>
      
      <button @click="addNewTarget" class="btn-primary">
        添加新目标
      </button>
    </div>

    <!-- 动态 Teleport 目标 -->
    <Teleport :to="selectedTarget">
      <div class="dynamic-content">
        <h3>动态传送内容</h3>
        <p>当前目标: <strong>{{ selectedTarget }}</strong></p>
        <p>内容可以动态传送到不同的位置</p>
      </div>
    </Teleport>

    <!-- 动态创建的目标容器 -->
    <div class="target-containers">
      <div 
        v-for="target in availableTargets" 
        :key="target.id"
        :class="['target-container', { active: selectedTarget === target.selector }]"
      >
        <h4>{{ target.name }}</h4>
        <p>选择器: <code>{{ target.selector }}</code></p>
      </div>
    </div>
  </div>
</template>

<script setup>
import { ref, reactive } from 'vue'

const targetId = ref(3)
const selectedTarget = ref('#target-1')

const availableTargets = reactive([
  { id: 1, name: '目标容器 1', selector: '#target-1' },
  { id: 2, name: '目标容器 2', selector: '#target-2' },
  { id: 3, name: 'Body', selector: 'body' }
])

const addNewTarget = () => {
  targetId.value++
  const newTarget = {
    id: targetId.value,
    name: `动态目标 ${targetId.value - 2}`,
    selector: `#target-${targetId.value}`
  }
  
  availableTargets.push(newTarget)
  selectedTarget.value = newTarget.selector
  
  // 动态创建目标容器
  nextTick(() => {
    const container = document.createElement('div')
    container.id = `target-${targetId.value}`
    container.className = 'target-container dynamic'
    container.innerHTML = `
      <h4>${newTarget.name}</h4>
      <p>选择器: <code>${newTarget.selector}</code></p>
    `
    document.querySelector('.target-containers').appendChild(container)
  })
}
</script>

<style scoped>
.dynamic-target-demo {
  padding: 20px;
  max-width: 1000px;
  margin: 0 auto;
}

.controls {
  display: flex;
  gap: 20px;
  align-items: end;
  margin: 20px 0;
  padding: 20px;
  background: #f8f9fa;
  border-radius: 8px;
}

.target-selector {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.target-selector label {
  font-weight: 600;
  color: #2c3e50;
}

.target-selector select {
  padding: 8px 12px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 14px;
  min-width: 200px;
}

.dynamic-content {
  padding: 20px;
  border: 3px solid #9b59b6;
  border-radius: 8px;
  background: #f8f5ff;
  margin: 20px 0;
}

.dynamic-content h3 {
  margin: 0 0 10px 0;
  color: #9b59b6;
}

.target-containers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 15px;
  margin-top: 30px;
}

.target-container {
  border: 2px solid #bdc3c7;
  border-radius: 8px;
  padding: 15px;
  background: #ecf0f1;
  min-height: 100px;
  transition: border-color 0.3s;
}

.target-container.active {
  border-color: #9b59b6;
  background: #f8f5ff;
}

.target-container h4 {
  margin: 0 0 10px 0;
  color: #2c3e50;
}

.target-container code {
  background: #34495e;
  color: #ecf0f1;
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 12px;
}

.target-container.dynamic {
  border-style: dashed;
  border-color: #e74c3c;
  background: #fff5f5;
}
</style>

六、 Teleport 的注意事项和最佳实践

6.1 注意事项

  1. 目标容器必须存在：确保 Teleport 的目标容器在组件挂载时已经存在
  2. SSR 兼容性：服务端渲染时 Teleport 不会被处理，需要在客户端激活
  3. 组件通信：传送的内容仍然保持与父组件的响应式连接
  4. 样式作用域：传送的内容不受原组件 scoped 样式的影响

6.2 最佳实践

<template>
  <div class="best-practices-demo">
    <h2>Teleport 最佳实践</h2>
    
    <div class="practice-item">
      <h3>1. 在 App.vue 中定义全局容器</h3>
      <button @click="showGlobalModal = true" class="btn-primary">
        打开全局模态框
      </button>
    </div>

    <div class="practice-item">
      <h3>2. 处理目标容器不存在的情况</h3>
      <button @click="showFallbackModal = true" class="btn-primary">
        打开备用模态框
      </button>
    </div>

    <div class="practice-item">
      <h3>3. 多个 Teleport 的顺序控制</h3>
      <button @click="addNotification('info')" class="btn-secondary">
        添加通知
      </button>
    </div>

    <!-- 最佳实践 1: 全局容器 -->
    <Teleport to="#global-modals">
      <GlobalModal 
        v-if="showGlobalModal"
        @close="showGlobalModal = false"
      />
    </Teleport>

    <!-- 最佳实践 2: 备用目标 -->
    <Teleport :to="getModalTarget">
      <FallbackModal
        v-if="showFallbackModal"
        @close="showFallbackModal = false"
      />
    </Teleport>

    <!-- 最佳实践 3: 通知系统 -->
    <Teleport to="#notifications">
      <div 
        v-for="notification in notifications" 
        :key="notification.id"
        class="notification-item"
      >
        {{ notification.message }}
      </div>
    </Teleport>
  </div>
</template>

<script setup>
import { ref, computed } from 'vue'
import GlobalModal from './GlobalModal.vue'
import FallbackModal from './FallbackModal.vue'

const showGlobalModal = ref(false)
const showFallbackModal = ref(false)
const notifications = ref([])
let notificationId = 0

// 最佳实践 2: 处理目标容器不存在的情况
const getModalTarget = computed(() => {
  // 检查目标容器是否存在
  return document.getElementById('fallback-modals') ? '#fallback-modals' : 'body'
})

// 最佳实践 3: 通知管理
const addNotification = (type) => {
  const id = ++notificationId
  notifications.value.push({
    id,
    type,
    message: `通知 #${id} - ${new Date().toLocaleTimeString()}`
  })
  
  // 自动移除通知
  setTimeout(() => {
    notifications.value = notifications.value.filter(n => n.id !== id)
  }, 3000)
}
</script>

<style scoped>
.best-practices-demo {
  padding: 20px;
  max-width: 800px;
  margin: 0 auto;
}

.practice-item {
  margin: 30px 0;
  padding: 20px;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  background: #fafafa;
}

.practice-item h3 {
  margin: 0 0 15px 0;
  color: #2c3e50;
}

.notification-item {
  padding: 10px 15px;
  margin: 5px 0;
  background: #3498db;
  color: white;
  border-radius: 4px;
  animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}
</style>

七、 总结

7.1 Teleport 的核心价值

  1. 解决 z-index 问题：确保重要内容显示在最上层
  2. 突破布局限制：不受父容器样式影响
  3. 更好的代码组织：逻辑相关的代码可以放在一起
  4. 提升可访问性：改善屏幕阅读器体验

7.2 适用场景

  • 模态框和对话框：需要显示在页面最顶层的交互组件
  • 通知和提示：全局的消息提示系统
  • 工具提示：需要精确定位的提示信息
  • 加载状态：全局的加载指示器
  • 侧边栏和面板：需要突破布局限制的浮动面板

7.3 性能考虑

  • DOM 操作：Teleport 涉及 DOM 节点的移动，但 Vue 会优化这个过程
  • 内存使用：传送的组件仍然在 Vue 的组件树中管理
  • 响应式保持：传送的内容保持完整的响应式特性

Teleport 是 Vue3 中一个非常强大的特性，它解决了前端开发中长期存在的布局和层级问题。通过合理使用 Teleport，可以构建出更加健壮、可维护的用户界面。

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