问如何在Angular 2中强制组件重新渲染？

EN

  constructor(private zone:NgZone) {
    // enable to for time travel
    this.appStore.subscribe((state) => {
        this.zone.run(() => {
            console.log('enabled time travel');
        });
    });

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

export class MyComponent {

    constructor(private cdr: ChangeDetectorRef) { }

    selected(item: any) {
        if (item == 'Department')
            this.isDepartment = true;
        else
            this.isDepartment = false;
        this.cdr.detectChanges();
    }

}

<ng-container *ngIf="_reload">
    components here 
</ng-container>

public _reload = true;

private reload() {
    setTimeout(() => this._reload = false);
    setTimeout(() => this._reload = true);
}