import { Injectable } from '@angular/core'; import { RouteReuseStrategy, DetachedRouteHandle, ActivatedRouteSnapshot } from '@angular/router'; @Injectable({ providedIn: 'root' }) export class RouteStrategyService implements RouteReuseStrategy { public static handlers: { [key: string]: DetachedRouteHandle } = {}; public static deleteRouteSnapshot(path: string): void { const name = path.replace(/\//g, '_'); if (RouteStrategyService.handlers[name]) { delete RouteStrategyService.handlers[name]; } } /** * 判断当前路由是否需要缓存 * 这个方法返回false时则路由发生变化并且其余方法会被调用 * @param {ActivatedRouteSnapshot} future * @param {ActivatedRouteSnapshot} curr * @returns {boolean} * @memberof CacheRouteReuseStrategy */ public shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean { return future.routeConfig === curr.routeConfig && JSON.stringify(future.params) === JSON.stringify(curr.params); } /** * 当离开当前路由时这个方法会被调用 * 如果返回 true 则 store 方法会被调用 * @param {ActivatedRouteSnapshot} route * @returns {boolean} * @memberof CacheRouteReuseStrategy */ public shouldDetach(route: ActivatedRouteSnapshot): boolean { if (!route.routeConfig || route.routeConfig.loadChildren) { return false } return true } /** * 将路由写入缓存 * 在这里具体实现如何缓存 RouteHandle * 提供了我们离开的路由和 RouteHandle * @param {ActivatedRouteSnapshot} route * @param {DetachedRouteHandle} detachedTree * @memberof CacheRouteReuseStrategy */ public store(route: ActivatedRouteSnapshot, detachedTree: DetachedRouteHandle): void { RouteStrategyService.handlers[this.getPath(route)] = detachedTree; } /** * 路由被导航 如果此方法返回 true 则触发 retrieve 方法 * 如果返回 false 这个组件将会被重新创建 * @param {ActivatedRouteSnapshot} route * @returns {boolean} * @memberof CacheRouteReuseStrategy */ public shouldAttach(route: ActivatedRouteSnapshot): boolean { return !!RouteStrategyService.handlers[this.getPath(route)]; } /** * 从缓存读取cached route * 提供当前路由的参数(刚打开的路由),并且返回一个缓存的 RouteHandle * 可以使用这个方法手动获取任何已被缓存的 RouteHandle * @param {ActivatedRouteSnapshot} route * @returns {(DetachedRouteHandle | null)} * @memberof CacheRouteReuseStrategy */ public retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle | null { return RouteStrategyService.handlers[this.getPath(route)] || null; } private getPath(route: ActivatedRouteSnapshot): string { // tslint:disable-next-line: no-string-literal return route['_routerState'].url.replace(/\//g, '_') + '_' + (route.routeConfig.loadChildren || route.routeConfig.component.toString().split('(')[0].split(' ')[1] ); } }