import { Component, ViewChildren, QueryList, ViewEncapsulation } from '@angular/core'; import { MatMenuTrigger } from '@angular/material'; @Component({ selector: 'app-header', templateUrl: './header.component.html', styleUrls: ['./header.component.css'], encapsulation: ViewEncapsulation.None, host: { '(window:resize)': 'onResize($event)' } }) export class HeaderComponent { @ViewChildren(MatMenuTrigger) trigger: QueryList; onResize(): void { this.trigger.map(item => { item.closeMenu() }); } onMenuOpened(currentMenu: number): void { this.trigger.map((item, index) => { if (index !== currentMenu) item.closeMenu(); }); } }