如何观察Angular 2中长格式的几个字段变化

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

@Component({
  selector: 'app-example',
  template: `
    <div>
      <input [(ngModel)]="field1" placeholder="Field 1">
      <input [(ngModel)]="field2" placeholder="Field 2">
      <input [(ngModel)]="field3" placeholder="Field 3">
    </div>
  `
})
export class ExampleComponent {
  field1: string;
  field2: string;
  field3: string;
}

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

@Component({
  selector: 'app-example',
  template: `
    <div>
      <input [(ngModel)]="field1" placeholder="Field 1">
      <input [(ngModel)]="field2" placeholder="Field 2">
      <input [(ngModel)]="field3" placeholder="Field 3">
    </div>
  `
})
export class ExampleComponent {
  @Input() field1: string;
  @Input() field2: string;
  @Input() field3: string;
}

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

@Component({
  selector: 'app-parent',
  template: `
    <app-example [field1]="field1" [field2]="field2" [field3]="field3"></app-example>
  `
})
export class ParentComponent {
  field1: string;
  field2: string;
  field3: string;

  // 监听字段变化
  onFieldChange() {
    console.log('Field 1:', this.field1);
    console.log('Field 2:', this.field2);
    console.log('Field 3:', this.field3);
  }
}