如何使用*n添加第n个子类对于ionic2，angular2

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

@Component({
  selector: 'base-class',
  template: '<p>This is the base class.</p>'
})
export class BaseClass {
  // 添加基类的属性和方法
}

import { Component } from '@angular/core';
import { BaseClass } from './base-class';

@Component({
  selector: 'child-class',
  template: '<p>This is the child class.</p>'
})
export class ChildClass extends BaseClass {
  // 添加子类的属性和方法
}

import { Component } from '@angular/core';
import { BaseClass } from './base-class';

@Component({
  selector: 'second-child-class',
  template: '<p>This is the second child class.</p>'
})
export class SecondChildClass extends BaseClass {
  // 添加第2个子类的属性和方法
}