如何检测Angular页面中的ngSwitch变化

import { Component, DoCheck } from '@angular/core';

@Component({
  selector: 'app-example',
  template: `
    <div [ngSwitch]="condition">
      <div *ngSwitchCase="'case1'">Case 1</div>
      <div *ngSwitchCase="'case2'">Case 2</div>
      <div *ngSwitchDefault>Default Case</div>
    </div>
  `,
})
export class ExampleComponent implements DoCheck {
  condition: string;

  ngDoCheck() {
    // 检测ngSwitch的变化
    console.log('ngSwitch changed');
  }
}

import { Component, ViewChild, AfterViewInit } from '@angular/core';

@Component({
  selector: 'app-example',
  template: `
    <div [ngSwitch]="condition">
      <div *ngSwitchCase="'case1'">Case 1</div>
      <div *ngSwitchCase="'case2'">Case 2</div>
      <div *ngSwitchDefault>Default Case</div>
    </div>
  `,
})
export class ExampleComponent implements AfterViewInit {
  @ViewChild('ngSwitchRef') ngSwitchRef: any;

  ngAfterViewInit() {
    // 监听ngSwitch的变化
    this.ngSwitchRef.ngSwitchChange.subscribe(() => {
      console.log('ngSwitch changed');
    });
  }
}