根据angular 4中的某些条件，从父项中的数组中删除特定的组件实例。

<ng-container *ngFor="let item of items; let i = index">
  <app-child [item]="item" [id]="i"></app-child>
</ng-container>

import { Component, ViewChildren, QueryList } from '@angular/core';
import { ChildComponent } from './child.component';

@Component({
  selector: 'app-parent',
  template: `
    <ng-container *ngFor="let item of items; let i = index">
      <app-child [item]="item" [id]="i"></app-child>
    </ng-container>
  `
})
export class ParentComponent {
  items: any[] = [...]; // 父组件的数组数据

  @ViewChildren(ChildComponent) children: QueryList<ChildComponent>;

  removeComponent(condition: any) {
    this.children.forEach(child => {
      if (condition) {
        child.destroy(); // 销毁特定的子组件实例
      }
    });
  }
}

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

@Component({
  selector: 'app-child',
  template: `
    <!-- 子组件的模板 -->
  `
})
export class ChildComponent implements OnDestroy {
  @Input() item: any;
  @Input() id: number;

  ngOnDestroy() {
    // 执行清理操作
  }
}