虚拟列表组件化
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300
src/App.vue
300
src/App.vue
@@ -1,289 +1,51 @@
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<script setup>
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import { ref, computed, onMounted, onBeforeUnmount } from 'vue'
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import VirtualList from './components/VirtualList.vue'
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/**
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* 虚拟列表配置参数
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*/
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const CONFIG = {
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itemHeight: 50, // 列表项基础高度
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itemPadding: 16, // 列表项上下padding总和(8px * 2)
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bufferCount: 2, // 上下缓冲区域的项目数量
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scrollDebounceTime: 16 // 滚动防抖时间（一帧）
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// 虚拟列表配置
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const listConfig = {
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itemHeight: 50,
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itemPadding: 16,
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bufferCount: 2,
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scrollDebounceTime: 16,
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}
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// 计算列表项实际总高度
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const totalItemHeight = CONFIG.itemHeight + CONFIG.itemPadding
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/**
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* 响应式状态管理
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*/
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const containerHeight = ref(0) // 容器高度
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const startIndex = ref(0) // 可视区域起始索引
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const selectedIndex = ref(0) // 当前选中项索引
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const isKeyboardNavigating = ref(false) // 键盘导航状态
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let keyboardTimer = null // 键盘导航定时器
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/**
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* DOM 引用
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*/
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const containerRef = ref(null)
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const listRef = ref(null)
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/**
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* 生成模拟数据
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* @returns {Array} 包含100条模拟项目数据的数组
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*/
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// 生成模拟数据
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const listData = Array.from({ length: 100 }, (_, i) => ({
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id: i,
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name: `project-${i + 1}`,
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path: `/Users/lanyuanxiaoyao/Project/IdeaProjects/project-${i + 1}`
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path: `/Users/lanyuanxiaoyao/Project/IdeaProjects/project-${i + 1}`,
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}))
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/**
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* 计算属性
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*/
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// 计算可视区域能显示的列表项数量
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const visibleCount = computed(() =>
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Math.floor(containerHeight.value / totalItemHeight)
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)
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// 计算当前需要渲染的数据
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const visibleData = computed(() => {
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const visibleStart = Math.max(0, startIndex.value - CONFIG.bufferCount)
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const visibleEnd = Math.min(
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listData.length,
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startIndex.value + visibleCount.value + CONFIG.bufferCount
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)
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return listData.slice(visibleStart, visibleEnd).map((item, index) => ({
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...item,
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index: visibleStart + index
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}))
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})
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// 计算列表偏移量
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const offsetY = computed(() =>
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Math.max(0, (startIndex.value - CONFIG.bufferCount) * totalItemHeight)
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)
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// 计算虚拟列表总高度
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const phantomHeight = computed(() =>
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listData.length * totalItemHeight
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)
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/**
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* 工具函数
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*/
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// 防抖函数
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const debounce = (fn, delay) => {
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let timer = null
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return (...args) => {
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if (timer) clearTimeout(timer)
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timer = setTimeout(() => fn.apply(null, args), delay)
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}
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// 选择处理
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const handleSelect = (item) => {
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console.log('Selected:', item)
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}
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/**
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* 事件处理函数
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*/
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// 更新容器高度
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const updateContainerHeight = () => {
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containerHeight.value = window.innerHeight
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}
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// 滚动处理
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const handleScroll = debounce(() => {
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if (!containerRef.value) return
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const scrollTop = containerRef.value.scrollTop
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const newStartIndex = Math.floor(scrollTop / totalItemHeight)
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if (newStartIndex !== startIndex.value) {
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startIndex.value = newStartIndex
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}
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}, CONFIG.scrollDebounceTime)
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// 鼠标移入处理
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const handleMouseEnter = (index) => {
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if (!isKeyboardNavigating.value) {
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selectedIndex.value = index
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ensureSelectedItemVisible()
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}
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}
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// 键盘导航处理
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const handleKeyDown = (e) => {
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if (e.key !== 'ArrowUp' && e.key !== 'ArrowDown') return
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e.preventDefault()
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isKeyboardNavigating.value = true
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if (keyboardTimer) clearTimeout(keyboardTimer)
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const containerTop = containerRef.value.scrollTop
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const currentVisibleStartIndex = Math.floor(containerTop / totalItemHeight)
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const currentVisibleEndIndex = currentVisibleStartIndex + visibleCount.value - 1
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const nextIndex = e.key === 'ArrowUp'
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? Math.max(0, selectedIndex.value - 1)
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: Math.min(listData.length - 1, selectedIndex.value + 1)
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// 自动滚动到可视区域
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if (nextIndex <= currentVisibleStartIndex) {
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containerRef.value.scrollTop = nextIndex * totalItemHeight
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} else if (nextIndex > currentVisibleEndIndex) {
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containerRef.value.scrollTop = (nextIndex - visibleCount.value + 1) * totalItemHeight
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}
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selectedIndex.value = nextIndex
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keyboardTimer = setTimeout(() => {
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isKeyboardNavigating.value = false
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}, 1000)
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}
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// 确保选中项在可视区域内
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const ensureSelectedItemVisible = () => {
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if (!containerRef.value) return
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const containerTop = containerRef.value.scrollTop
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const containerHeight = containerRef.value.clientHeight
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const visibleCount = Math.floor(containerHeight / totalItemHeight)
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const currentVisibleStartIndex = Math.floor(containerTop / totalItemHeight)
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const currentVisibleEndIndex = currentVisibleStartIndex + visibleCount - 1
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if (selectedIndex.value < currentVisibleStartIndex) {
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containerRef.value.scrollTop = selectedIndex.value * totalItemHeight
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} else if (selectedIndex.value > currentVisibleEndIndex) {
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containerRef.value.scrollTop = (selectedIndex.value - visibleCount + 1) * totalItemHeight
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}
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}
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/**
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* 生命周期钩子
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*/
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onMounted(() => {
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if (containerRef.value) {
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containerRef.value.addEventListener('scroll', handleScroll)
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}
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updateContainerHeight()
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window.addEventListener('resize', updateContainerHeight)
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window.addEventListener('keydown', handleKeyDown)
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})
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onBeforeUnmount(() => {
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if (containerRef.value) {
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containerRef.value.removeEventListener('scroll', handleScroll)
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}
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window.removeEventListener('resize', updateContainerHeight)
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window.removeEventListener('keydown', handleKeyDown)
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if (keyboardTimer) {
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clearTimeout(keyboardTimer)
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}
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})
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</script>
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<template>
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<!-- 原有的虚拟列表容器 -->
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<div
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ref="containerRef"
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class="virtual-list-container"
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:style="{ height: `${containerHeight}px` }"
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tabindex="0"
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>
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<div
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ref="listRef"
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class="virtual-list-phantom"
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:style="{ height: `${phantomHeight}px` }"
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>
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<div
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class="virtual-list"
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:style="{ transform: `translateY(${offsetY}px)` }"
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>
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<div
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v-for="item in visibleData"
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:key="item.index"
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class="list-item"
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:class="{ 'selected': selectedIndex === item.index }"
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:style="{ height: `${CONFIG.itemHeight}px` }"
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@mouseenter="handleMouseEnter(item.index)"
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>
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<div class="item-icon">
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<svg viewBox="0 0 24 24" width="16" height="16">
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<circle cx="12" cy="12" r="10" fill="#1a1a1a" />
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</svg>
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</div>
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<div class="item-content">
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<div class="item-name">{{ item.name }}</div>
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<div class="item-path">{{ item.path }}</div>
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</div>
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</div>
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</div>
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</div>
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<div class="app-container">
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<VirtualList
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:data="listData"
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:config="listConfig"
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@select="handleSelect"
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/>
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</div>
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</template>
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<style scoped>
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.virtual-list-container {
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overflow-y: auto;
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border: 1px solid #ccc;
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position: relative;
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background-color: #f4f4f4;
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<style>
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html, body {
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margin: 0;
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padding: 0;
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height: 100%;
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}
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.virtual-list-phantom {
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position: relative;
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width: 100%;
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}
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.virtual-list {
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position: absolute;
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top: 0;
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left: 0;
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width: 100%;
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}
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.list-item {
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padding: 8px 16px;
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display: flex;
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align-items: center;
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gap: 12px;
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border-bottom: 1px solid #e8e8e8;
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transition: background-color 0.2s;
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cursor: pointer;
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background-color: white;
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}
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.list-item.selected {
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background-color: #e6f7ff;
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}
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.item-icon {
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flex-shrink: 0;
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width: 24px;
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height: 24px;
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display: flex;
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align-items: center;
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justify-content: center;
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}
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.item-content {
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flex: 1;
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min-width: 0;
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display: flex;
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flex-direction: column;
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gap: 4px;
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}
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.item-name {
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font-size: 14px;
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color: #1a1a1a;
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font-weight: 500;
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}
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.item-path {
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font-size: 12px;
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color: #666;
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white-space: nowrap;
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overflow: hidden;
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text-overflow: ellipsis;
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#app {
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height: 100%;
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}
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</style>
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<style scoped>
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.app-container {
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height: 100%;
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}
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</style>
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