fix: 将 code-review-skill 从子模块转为普通目录
This commit is contained in:
baozaotumao
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# Angular Code Review Guide
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> Angular 17+ 代码审查指南，覆盖 Signals、Standalone 组件、RxJS 反模式、Zoneless 变更检测、模板最佳实践及性能优化等核心主题。
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## 目录
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- [Signals 与变更检测](#signals-与变更检测)
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- [Standalone 组件迁移](#standalone-组件迁移)
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- [RxJS 反模式](#rxjs-反模式)
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- [Zoneless 变更检测](#zoneless-变更检测)
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- [模板最佳实践](#模板最佳实践)
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- [性能优化](#性能优化)
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- [Review Checklist](#review-checklist)
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---
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## Signals 与变更检测
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### Signal + OnPush 自动触发变更检测
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```typescript
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// ❌ 可变状态 + OnPush = 界面不更新
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@Component({
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changeDetection: ChangeDetectionStrategy.OnPush,
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template: `<p>{{ data.name }}</p>`,
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})
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export class UserProfile {
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data = { name: 'Alice' };
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changeName() { this.data.name = 'Bob'; } // UI 不会更新！
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}
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// ✅ Signal + OnPush = 自动变更检测
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@Component({
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changeDetection: ChangeDetectionStrategy.OnPush,
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template: `<p>{{ name() }}</p>`,
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})
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export class UserProfile {
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name = signal('Alice');
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changeName() { this.name.set('Bob'); } // 自动触发 CD
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}
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```
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### @Input() 对象变异不会被 OnPush 检测
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```typescript
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// ❌ 变异 Input 对象——引用不变，OnPush 不检测
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@Input() config!: Config;
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updateConfig() { this.config.theme = 'dark'; }
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// ✅ 创建新引用
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updateConfig() { this.config = { ...this.config, theme: 'dark' }; }
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```
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### computed() 用于派生状态
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```typescript
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// ❌ effect 用于同步状态——反模式，可能触发额外 CD 周期
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export class CartComponent {
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total = signal(0);
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discounted = signal(0);
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constructor() {
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effect(() => this.discounted.set(this.total() * 0.9));
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}
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}
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// ✅ computed 用于派生状态——惰性计算，无副作用
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export class CartComponent {
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total = signal(0);
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discounted = computed(() => this.total() * 0.9);
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}
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```
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### effect() 中 Signal 读取在 await 后不会被追踪
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```typescript
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// ❌ await 之后读取 Signal——依赖未被追踪
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effect(async () => {
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const data = await fetchUserData();
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console.log(`Theme: ${theme()}`); // theme() 未被追踪！
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});
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// ✅ 在 await 之前同步读取
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effect(async () => {
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const currentTheme = theme(); // 同步读取，被追踪
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const data = await fetchUserData();
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console.log(`Theme: ${currentTheme}`);
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});
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```
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### effect 只在特定场景使用
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```typescript
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// ❌ 用 effect 同步两个 Signal——永远用 computed
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effect(() => { this.filtered.set(this.items().filter(i => i.active)); });
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// ✅ effect 的合理场景：DOM 操作、分析日志、订阅外部源
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effect(() => {
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const canvas = this.canvasRef.nativeElement;
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const ctx = canvas.getContext('2d');
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ctx.fillStyle = this.color();
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ctx.fillRect(0, 0, this.size(), this.size());
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});
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// 💡 "There are no situations where effect is good,
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// only situations where it is appropriate."
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```
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---
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## Standalone 组件迁移
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### Angular 19+ standalone 是默认值
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```typescript
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// ❌ Legacy NgModule 组件
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@Component({
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selector: 'old-component',
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standalone: false,
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})
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export class OldComponent {}
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// ✅ 现代 Standalone 组件（Angular 19+ standalone 是默认值）
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@Component({
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selector: 'user-profile',
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imports: [ProfilePhoto, RouterLink],
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template: `<profile-photo /><a routerLink="/edit">Edit</a>`,
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})
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export class UserProfile {}
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```
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### 审查标记
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```typescript
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// ⚠️ 需要迁移的信号：
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// 1. standalone: false
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// 2. @NgModule declarations
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// 3. 组件通过 NgModule 而非直接 import
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// ✅ 迁移路径：
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// 1. 删除 standalone: false
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// 2. 将依赖添加到组件的 imports 数组
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// 3. 如果不再有 declarations，删除 NgModule
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```
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---
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## RxJS 反模式
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### subscribe() 必须配 takeUntilDestroyed
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```typescript
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// ❌ 裸 subscribe——内存泄漏！组件销毁后仍继续接收数据
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@Component({ /* ... */ })
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export class UserProfile implements OnInit {
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ngOnInit() {
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this.data$.subscribe(data => this.processData(data));
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}
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}
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// ✅ takeUntilDestroyed——自动在组件销毁时取消（需在构造函数或注入上下文中调用）
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@Component({ /* ... */ })
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export class UserProfile {
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constructor() {
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this.data$.pipe(takeUntilDestroyed()).subscribe(data => {
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this.processData(data);
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});
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}
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}
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// ✅ 在构造函数外使用——传入 DestroyRef
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@Component({ /* ... */ })
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export class UserProfile {
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private destroyRef = inject(DestroyRef);
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startListening() {
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this.data$.pipe(takeUntilDestroyed(this.destroyRef)).subscribe(/* ... */);
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}
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}
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```
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### toSignal 优于 AsyncPipe
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```typescript
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// ❌ AsyncPipe——需要导入，模板中有 | async
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@Component({
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imports: [AsyncPipe],
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template: `{{ data$ | async }}`,
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})
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// ✅ toSignal——自动取消订阅，可在任何地方使用
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export class UserProfile {
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data = toSignal(this.data$, { initialValue: null });
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// 模板直接用 data()
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}
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```
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### 避免重复 toSignal 调用
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```typescript
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// ❌ toSignal 每次调用都创建新订阅
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getData() {
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return toSignal(this.http.get('/api/data'));
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}
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// ✅ 存储结果
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data = toSignal(this.http.get('/api/data'), { initialValue: null });
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```
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---
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## Zoneless 变更检测
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### 普通属性变异不会被检测（Angular 21+）
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```typescript
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// ❌ Zoneless 下普通属性赋值不触发 CD
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export class UserService {
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user: User | null = null;
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loadUser() { this.user = fetchResult; } // 不触发！
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}
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// ✅ Signal 自动触发 CD
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export class UserService {
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private _user = signal<User | null>(null);
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readonly user = this._user.asReadonly();
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loadUser() { this._user.set(fetchResult); }
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}
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```
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### NgZone API 在 Zoneless 中失效
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```typescript
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// ❌ NgZone.onStable 在 zoneless 中永远不会触发
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ngZone.onStable.subscribe(() => { /* 永远不触发 */ });
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// ✅ 使用 afterNextRender
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afterNextRender({ write: () => { /* CD 之后执行 */ } });
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```
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### Reactive Forms 变异需要 markForCheck
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```typescript
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// ❌ Reactive Forms 的 setValue/patchValue 在 zoneless 中不自动调度 CD
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this.form.patchValue({ name: 'Alice' }); // UI 可能不更新
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// ✅ 手动标记或通过 Signal 反映
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this.form.patchValue({ name: 'Alice' });
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this.cdr.markForCheck();
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```
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### Zoneless 下有效的 CD 触发器
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| 触发器 | 说明 |
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|--------|------|
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| `signal.set()` / `.update()` | Signal 更新自动触发 |
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| `ChangeDetectorRef.markForCheck()` | 手动标记 |
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| `ComponentRef.setInput()` | 输入绑定 |
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| 模板事件监听器回调 | 用户交互 |
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---
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## 模板最佳实践
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### 复杂逻辑提取为 computed Signal
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```typescript
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// ❌ 模板中复杂表达式
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template: `<div *ngIf="items.filter(i => i.active).length > 0 && user.role === 'admin'">`
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// ✅ 提取为 computed
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filteredItems = computed(() => this.items().filter(i => i.active));
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shouldShow = computed(() => this.filteredItems().length > 0 && this.user().role === 'admin');
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template: `@if (shouldShow()) { <div>...</div> }`
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```
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### 原生绑定优于 NgClass / NgStyle
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```typescript
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// ❌ NgClass/NgStyle——额外指令开销
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template: `<div [ngClass]="{active: isActive}" [ngStyle]="{'color': textColor}">`
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// ✅ 原生 class/style 绑定——性能更好
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template: `<div [class.active]="isActive" [style.color]="textColor">`
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```
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### 模板专用成员标记 protected
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```typescript
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// ❂ 模板专用方法暴露为 public
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export class UserProfile {
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formatName(name: string) { return name.trim(); }
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}
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// ✅ 模板专用成员用 protected
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export class UserProfile {
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protected formatName(name: string) { return name.trim(); }
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}
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```
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### Angular 管理的属性标记 readonly
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```typescript
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// ❌ input/output/model 可被意外覆盖
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userId = input<string>();
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userSaved = output<void>();
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// ✅ readonly 防止意外赋值
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readonly userId = input<string>();
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readonly userSaved = output<void>();
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readonly userName = model<string>();
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```
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### 命名规范：操作名而非事件名
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```typescript
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// ❌ 以事件命名
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template: `<button (click)="handleClick()">Save</button>`
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// ✅ 以操作命名
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template: `<button (click)="saveUserData()">Save</button>`
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```
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---
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## 性能优化
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### effect 是最后手段——优先 computed
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```typescript
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// ❌ effect 用于状态同步——触发额外 CD，可能无限循环
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effect(() => {
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this.filteredItems.set(this.items().filter(i => i.active));
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});
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// ✅ computed——惰性计算，无副作用，无额外 CD
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filteredItems = computed(() => this.items().filter(i => i.active));
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```
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### afterRenderEffect 分离读写阶段
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```typescript
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// ❌ 无阶段指定 = mixedReadWrite = 额外 DOM 回流
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afterRenderEffect(() => {
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const height = el.offsetHeight; // 读
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el.style.height = height + 10 + 'px'; // 写
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});
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// ✅ 分离阶段减少回流
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afterRenderEffect({
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earlyRead: () => el.offsetHeight,
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write: (height) => { el.style.height = height() + 10 + 'px'; },
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read: () => verifyLayout(),
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});
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```
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### inject() 优于构造函数注入
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```typescript
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// ❌ 构造函数注入——多依赖时难以阅读
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export class UserService {
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constructor(
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private http: HttpClient,
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private router: Router,
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private auth: AuthService,
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) {}
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}
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// ✅ inject()——更好的类型推断和可读性
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export class UserService {
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private http = inject(HttpClient);
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private router = inject(Router);
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private auth = inject(AuthService);
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}
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```
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---
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## Review Checklist
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### Signals 与变更检测
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- [ ] Signal + OnPush 用于模板状态（非可变对象）
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- [ ] `@Input()` 对象通过新引用更新（非变异）
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- [ ] 派生状态用 `computed()`，不用 `effect()`
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- [ ] `effect()` 中 Signal 读取在 `await` 之前
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- [ ] `effect()` 只用于 DOM 操作、日志、外部源订阅
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### Standalone 组件
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- [ ] 无 `standalone: false`（Angular 19+）
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- [ ] 组件通过 `imports` 数组导入依赖
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- [ ] 无不必要的 `@NgModule`
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### RxJS
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- [ ] `.subscribe()` 配 `takeUntilDestroyed` 或 `async` pipe
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- [ ] 优先 `toSignal` 而非 `AsyncPipe`
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- [ ] 无重复 `toSignal` 调用
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### Zoneless
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- [ ] 模板状态通过 Signal 管理（非普通属性）
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- [ ] 无 `NgZone.onStable` / `NgZone.onMicrotaskEmpty`
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- [ ] Reactive Forms 变异后有 `markForCheck()`
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### 模板
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- [ ] 复杂逻辑提取为 `computed` Signal
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- [ ] 使用原生 `[class]`/`[style]` 而非 `NgClass`/`NgStyle`
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- [ ] 模板专用成员标记 `protected`
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- [ ] `input`/`output`/`model` 属性标记 `readonly`
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- [ ] 事件处理器以操作命名（`saveData` 而非 `handleClick`）
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### 性能
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- [ ] `effect()` 不用于状态同步
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- [ ] `afterRenderEffect` 分离读写阶段
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- [ ] `inject()` 用于依赖注入
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Reference in New Issue
Block a user