在惰性加载的组件中,每当导航到该组件时,Angular 都会重新创建组件实例并重新渲染该组件,这可能会导致性能问题。一个解决方法是利用 Angular 的 RouteReuseStrategy 策略,通过缓存上次创建的组件实例来避免重复渲染。
import { RouteReuseStrategy, ActivatedRouteSnapshot, DetachedRouteHandle } from '@angular/router';
export class CustomRouteReuseStrategy implements RouteReuseStrategy {
shouldDetach(route: ActivatedRouteSnapshot): boolean {
return false;
}
store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): void {
}
shouldAttach(route: ActivatedRouteSnapshot): boolean {
return false;
}
retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle|null {
return null;
}
shouldReuseRoute(future: ActivatedRouteSnapshot, current: ActivatedRouteSnapshot): boolean {
// check if the component is the same
return future.component === current.component;
}
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { RouterModule, RouteReuseStrategy } from '@angular/router';
import { AppComponent } from './app.component';
import { CustomRouteReuseStrategy } from './custom-route-reuse-strategy';
@NgModule({
imports: [ BrowserModule, RouterModule.forRoot(routes) ],
declarations: [ AppComponent ],
providers: [
{ provide: RouteReuseStrategy, useClass: CustomRouteReuseStrategy }
],
bootstrap: [ AppComponent ]
})
export class AppModule {}
以上代码将不会在每次导航到同一惰性加载组件时重新创建组件实例。在大多数情况下,这样可以减少不必要的渲染,提高性能。
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