在Angular 9中使用OAuth2和OIDC进行身份验证时，可能会遇到一些路由问题。以下是一些解决这些问题的方法和代码示例：

1. 问题：在进行OAuth2身份验证后，回调URL重定向到根路径而不是原始请求的URL。

解决方法：在app.module.ts文件中的@NgModule装饰器中添加一个providers配置项，将redirectUri设置为原始请求的URL。

import { NgModule } from '@angular/core';
import { AuthModule, OidcSecurityService, OpenIDImplicitFlowConfiguration } from 'angular-auth-oidc-client';

@NgModule({
  imports: [
    // other imports
    AuthModule.forRoot(),
  ],
  providers: [
    OidcSecurityService,
    {
      provide: 'ORIGIN_URL',
      useFactory: (getOriginUrl),
      deps: [OidcSecurityService],
    }
  ],
})
export class AppModule {
  constructor(private oidcSecurityService: OidcSecurityService) {
    const openIDImplicitFlowConfiguration = new OpenIDImplicitFlowConfiguration();
    openIDImplicitFlowConfiguration.stsServer = 'https://your-identity-provider.com';
    openIDImplicitFlowConfiguration.redirect_url = this.originUrl + '/signin-oidc';
    openIDImplicitFlowConfiguration.post_logout_redirect_uri = this.originUrl + '/signout-callback-oidc';
    this.oidcSecurityService.setupModule(openIDImplicitFlowConfiguration);
  }
  private get originUrl() {
    return window.location.origin;
  }
}

export function getOriginUrl(oidcSecurityService: OidcSecurityService) {
  return oidcSecurityService.getConfig().redirect_url.match(/^(.+\/)/)[0];
}

2. 问题：在进行OAuth2身份验证后，应用程序无法路由到受保护的组件。

解决方法：在相应的路由上添加一个AuthGuard，用于检查用户是否已登录。

import { Injectable } from '@angular/core';
import { CanActivate, Router } from '@angular/router';
import { OidcSecurityService } from 'angular-auth-oidc-client';

@Injectable()
export class AuthGuard implements CanActivate {
  constructor(private oidcSecurityService: OidcSecurityService, private router: Router) {}

  canActivate(): boolean {
    if (this.oidcSecurityService.isAuthenticated()) {
      return true;
    } else {
      this.router.navigate(['/login']);
      return false;
    }
  }
}

然后，在路由配置中使用AuthGuard：

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { AuthGuard } from './auth.guard';
import { HomeComponent } from './home.component';

const routes: Routes = [
  { path: '', component: HomeComponent, canActivate: [AuthGuard] },
  // other routes
];

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

这些解决方法可以帮助您在Angular 9中解决OAuth2、OIDC和路由问题。请根据您的具体需求进行调整和扩展。