在angular5的app.routes.ts中定义带约束(应包含字符串)的路径

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { HomeComponent } from './home.component';
import { AboutComponent } from './about.component';
import { ContactComponent } from './contact.component';

// 定义路由守卫函数
function checkStringConstraint(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): boolean {
  const paramValue = route.params['param']; // 获取路径参数值
  return typeof paramValue === 'string'; // 判断参数值是否为字符串
}

const routes: Routes = [
  { path: 'home', component: HomeComponent },
  { path: 'about/:param', component: AboutComponent, canActivate: [checkStringConstraint] },
  { path: 'contact', component: ContactComponent }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }