1:写成这样
export class a类 extends b类 implements OnInit {
}
2:在引入服务依赖的时候写成这样
constructor(public technicalProductsService: TechnicalProductsService) {
super(technicalProductsService);
}
3:b类的属性在a类重新定义的时候应该在a类的constructor函数里面使用this改写
constructor(public technicalProductsService: TechnicalProductsService) {
super(technicalProductsService);
this.articleClassify = 4;
}