import { Component, ViewChild, AfterViewInit, ViewEncapsulation } from '@angular/core'; import { jqxDropDownButtonComponent } from 'jqwidgets-ng/jqxdropdownbutton'; import { jqxTreeComponent } from 'jqwidgets-ng/jqxtree'; @Component({ selector: 'app-root', templateUrl: './app.component.html', styleUrls: ['./app.component.css'], encapsulation: ViewEncapsulation.None }) export class AppComponent implements AfterViewInit { @ViewChild('myDropDownButton', { static: false }) myDropDownButton: jqxDropDownButtonComponent; @ViewChild('myTree', { static: false }) myTree: jqxTreeComponent; ngAfterViewInit(): void { this.myDropDownButton.setContent('