要在Angular路由器中保持状态并响应用户输入，可以使用路由器的参数传递和订阅机制。下面是一个示例解决方法：

1. 配置路由器：

   // app-routing.module.ts
   import { NgModule } from '@angular/core';
   import { Routes, RouterModule } from '@angular/router';
   import { HomeComponent } from './home.component';
   import { ChildComponent } from './child.component';
   
   const routes: Routes = [
     { path: '', component: HomeComponent },
     { path: 'child/:id', component: ChildComponent }
   ];
   
   @NgModule({
     imports: [RouterModule.forRoot(routes)],
     exports: [RouterModule]
   })
   export class AppRoutingModule { }
   

2. 在父组件中定义一个共享状态的服务：

   // state.service.ts
   import { Injectable } from '@angular/core';
   import { Subject } from 'rxjs';
   
   @Injectable({
     providedIn: 'root'
   })
   export class StateService {
     private stateSource = new Subject();
     state$ = this.stateSource.asObservable();
   
     setState(state: string) {
       this.stateSource.next(state);
     }
   }
   

3. 在父组件中订阅状态的变化，并在用户输入时更新状态：

   // home.component.ts
   import { Component } from '@angular/core';
   import { StateService } from './state.service';
   
   @Component({
     selector: 'app-home',
     template: `
       
   Home Component
       
     `
   })
   export class HomeComponent {
     state: string;
   
     constructor(private stateService: StateService) {}
   
     updateState() {
       this.stateService.setState(this.state);
     }
   }
   

4. 在子组件中订阅状态的变化，并在状态变化时更新视图：

   // child.component.ts
   import { Component, OnDestroy } from '@angular/core';
   import { ActivatedRoute } from '@angular/router';
   import { StateService } from './state.service';
   import { Subscription } from 'rxjs';
   
   @Component({
     selector: 'app-child',
     template: `
       
   Child Component
       
   Parent state: {{ parentState }}
       
   Child state: {{ childState }}
     `
   })
   export class ChildComponent implements OnDestroy {
     parentState: string;
     childState: string;
     private stateSubscription: Subscription;
   
     constructor(
       private route: ActivatedRoute,
       private stateService: StateService
     ) {
       this.parentState = this.route.snapshot.paramMap.get('id');
   
       this.stateSubscription = this.stateService.state$.subscribe((state) => {
         this.childState = state;
       });
     }
   
     ngOnDestroy() {
       this.stateSubscription.unsubscribe();
     }
   }
   

这样，当用户在父组件中输入文本时，状态会被更新并通过服务传递给子组件，子组件会相应地更新视图。