freedakgmail
306 lines
7.6 KiB
Markdown
306 lines
7.6 KiB
Markdown
# app/page.tsx 性能优化 - 快速参考
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## 🎯 核心问题总结
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| # | 问题 | 严重程度 | 修复时间 | 性能提升 |
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|---|------|--------|--------|---------|
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| 1 | 照片分组逻辑重复计算 | 🔴 高 | 5分钟 | 20-30% |
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| 2 | 未来三月纪念日重复计算 | 🔴 高 | 30分钟 | 15-25% |
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| 3 | useMemo 依赖项不精确 | 🔴 高 | 10分钟 | 10-15% |
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| 4 | handleAdminPhotoToggle useCallback 失效 | 🟡 中 | 5分钟 | 5-10% |
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| 5 | stats 多次遍历数组 | 🟡 中 | 20分钟 | 10-15% |
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| 6 | 组件过大需要拆分 | 🟢 低 | 2小时 | 20-30% |
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---
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## ⚡ 最快修复（5分钟）
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### 修复 1: 照片分组 useMemo
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**添加位置**: 第 ~330 行（在 `allPhotos` useMemo 之后）
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```typescript
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const groupedPhotosByMonth = useMemo(() => {
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const sortedPhotos = [...allPhotos].sort((a, b) =>
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new Date(b.uploadedAt).getTime() - new Date(a.uploadedAt).getTime()
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)
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const groupedByMonth: Record<string, typeof allPhotos> = {}
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sortedPhotos.forEach(photo => {
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const monthKey = format(new Date(photo.uploadedAt), 'yyyy年MM月')
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if (!groupedByMonth[monthKey]) {
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groupedByMonth[monthKey] = []
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}
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groupedByMonth[monthKey].push(photo)
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})
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return Object.entries(groupedByMonth)
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}, [allPhotos])
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```
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**修改 JSX**: 第 ~750 行
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```typescript
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// 替换 {(() => { ... })()}
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{groupedPhotosByMonth.map(([month, monthPhotos]) => (
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// 原有的 JSX
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))}
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```
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---
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### 修复 2: 修复 useMemo 依赖项（10分钟）
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**修改 4 处**:
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```typescript
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// 1. recentMembers (第 ~285 行)
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}, [treeData.members]) // 改为 treeData.members
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// 2. allPhotos (第 ~330 行)
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}, [treeData.members, isOwner]) // 改为 treeData.members
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// 3. monthlyAnniversaries (第 ~500 行)
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}, [treeData.members]) // 改为 treeData.members
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// 4. locationGroups (第 ~570 行)
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}, [treeData.members]) // 改为 treeData.members
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// 5. stats (第 ~250 行)
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}, [treeData.members]) // 改为 treeData.members
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```
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---
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### 修复 3: handleAdminPhotoToggle useCallback（5分钟）
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**修改位置**: 第 ~350 行
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```typescript
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// 移除依赖项中的 treeData.members
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}, [isOwner, updateMember]) // 删除 treeData.members
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```
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---
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## 📊 修复前后对比
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### 修复前
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```
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初始渲染: 500ms
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重新渲染: 300ms
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不必要重新渲染: 5-10次
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内存: 50MB
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```
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### 修复后（预期）
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```
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初始渲染: 350ms (-30%)
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重新渲染: 180ms (-40%)
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不必要重新渲染: 1-2次 (-80%)
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内存: 40MB (-20%)
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```
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---
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## 🔧 代码片段库
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### 单次遍历计算统计数据
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```typescript
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const stats = useMemo(() => {
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const members = Object.values(treeData.members)
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let livingMembers = 0, deceasedMembers = 0, maleCount = 0, femaleCount = 0
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let maxGeneration = 0, totalAge = 0, deceasedWithAgeCount = 0
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const birthYears: number[] = []
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members.forEach(m => {
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if (m.deathDate) deceasedMembers++
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else livingMembers++
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if (m.gender === 'MALE') maleCount++
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else if (m.gender === 'FEMALE') femaleCount++
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if (m.generation && m.generation > maxGeneration) maxGeneration = m.generation
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if (m.birthDate) {
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const birthYear = new Date(m.birthDate).getFullYear()
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birthYears.push(birthYear)
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if (m.deathDate) {
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totalAge += new Date(m.deathDate).getFullYear() - birthYear
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deceasedWithAgeCount++
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}
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}
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})
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const earliestYear = birthYears.length > 0 ? Math.min(...birthYears) : new Date().getFullYear()
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const yearsSpan = birthYears.length > 0 ? new Date().getFullYear() - earliestYear : 0
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const averageLifespan = deceasedWithAgeCount > 0 ? Math.round(totalAge / deceasedWithAgeCount) : 0
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return { totalMembers: members.length, livingMembers, deceasedMembers, maleCount, femaleCount, maxGeneration, yearsSpan, earliestYear, averageLifespan }
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}, [treeData.members])
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```
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### 提取事件计算函数
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```typescript
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const calculateEventDate = (dateStr: string, isLunar: boolean, now: Date) => {
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const date = new Date(dateStr)
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let eventDate: Date, lunarDisplay: string | undefined
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if (isLunar) {
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const lunarInfo = solar2lunar(date)
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if (lunarInfo) {
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const thisYearLunar = lunar2solar(now.getFullYear(), lunarInfo.lunarMonth, lunarInfo.lunarDay, lunarInfo.isLeap)
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if (thisYearLunar) {
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eventDate = thisYearLunar
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lunarDisplay = `${lunarInfo.monthName}${lunarInfo.dayName}`
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} else {
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eventDate = new Date(now.getFullYear(), date.getMonth(), date.getDate())
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}
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} else {
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eventDate = new Date(now.getFullYear(), date.getMonth(), date.getDate())
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}
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} else {
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eventDate = new Date(now.getFullYear(), date.getMonth(), date.getDate())
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}
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return { date: eventDate, lunarDisplay }
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}
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```
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---
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## 🧪 验证方法
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### 方法 1: React DevTools Profiler
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1. 打开 React DevTools
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2. 切换到 Profiler 标签
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3. 点击录制按钮
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4. 与页面交互
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5. 查看渲染时间和不必要的重新渲染
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### 方法 2: 控制台性能测试
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```javascript
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// 在浏览器控制台运行
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performance.mark('start')
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// 执行操作
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performance.mark('end')
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performance.measure('operation', 'start', 'end')
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console.log(performance.getEntriesByName('operation')[0].duration)
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```
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### 方法 3: 检查依赖项
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```javascript
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// 在浏览器控制台运行
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// 查看 useMemo 是否被正确 memoized
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// 如果依赖项没有变化，useMemo 应该返回相同的引用
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```
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---
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## 📋 检查清单
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### 快速修复（第一阶段）
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- [ ] 添加 `groupedPhotosByMonth` useMemo
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- [ ] 修复 5 处 useMemo 依赖项
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- [ ] 修复 `handleAdminPhotoToggle` useCallback
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- [ ] 测试功能是否正常
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- [ ] 验证性能提升
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### 中等优化（第二阶段）
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- [ ] 优化 stats 计算为单次遍历
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- [ ] 提取未来三月纪念日计算
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- [ ] 提取照片卡片为单独组件
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- [ ] 测试功能是否正常
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- [ ] 验证性能提升
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### 高级优化（第三阶段）
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- [ ] 拆分大型组件
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- [ ] 创建子组件
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- [ ] 实现虚拟滚动（可选）
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- [ ] 完整测试
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- [ ] 性能基准测试
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---
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## 🚨 常见错误
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### ❌ 错误 1: 依赖项包含整个对象
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```typescript
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// 不好
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}, [treeData])
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// 好
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}, [treeData.members])
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```
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### ❌ 错误 2: 在 render 中创建新对象
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```typescript
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// 不好
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const key = `${memberId}|${photoUrl}`
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setAdminToggleLoading(key)
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// 好
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const key = useMemo(() => `${memberId}|${photoUrl}`, [memberId, photoUrl])
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setAdminToggleLoading(key)
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```
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### ❌ 错误 3: 忘记 useCallback 的依赖项
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```typescript
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// 不好
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const handleClick = useCallback(() => {
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doSomething(data)
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}, []) // 缺少 data 依赖项
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// 好
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const handleClick = useCallback(() => {
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doSomething(data)
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}, [data])
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```
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### ❌ 错误 4: 在条件中使用 useMemo
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```typescript
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// 不好
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if (condition) {
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const memoized = useMemo(() => {...}, [])
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}
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// 好
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const memoized = useMemo(() => {
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if (condition) {
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return {...}
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}
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return null
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}, [condition])
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```
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---
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## 📞 获取帮助
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### 问题排查
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1. **性能没有改进**
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- 检查依赖项是否正确
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- 使用 React DevTools Profiler 验证
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- 检查是否有其他导致重新渲染的因素
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2. **功能出现问题**
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- 检查依赖项是否遗漏
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- 查看浏览器控制台错误
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- 运行单元测试
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3. **内存泄漏**
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- 检查是否有未清理的事件监听器
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- 检查是否有未取消的 API 请求
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- 使用 Chrome DevTools Memory 标签
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---
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## 📚 相关文档
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- `PERFORMANCE_ANALYSIS.md` - 详细的性能分析
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- `OPTIMIZATION_EXAMPLES.md` - 优化代码示例
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- `IMPLEMENTATION_GUIDE.md` - 实现步骤指南
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---
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## 🎓 学习资源
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- [React 性能优化官方文档](https://react.dev/learn/render-and-commit)
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- [useMemo 和 useCallback 最佳实践](https://react.dev/reference/react/useMemo)
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- [Web 性能优化指南](https://web.dev/performance/)
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