嗨,我想在Angular 4应用程序上单击编辑按钮后将焦点设置在输入元素上.
首先我尝试了Renderer2,但它似乎并不适用于此目的.
现在我正在尝试使用@ViewChild,我总是得到未定义的价值.
我事件尝试实现AfterViewInit并在加载后立即记录该元素,但我仍然得到’未定义’.请帮忙..
import { Component,OnInit,Input,Output,EventEmitter,Renderer2,ViewChild,AfterViewInit } from '@angular/core'; import { NgIf } from '@angular/common'; import { DataService } from '../data.service'; import { NgForm } from '@angular/forms'; @Component({ selector: 'app-artist-list-item',template: ` <button class="w3-button w3-circle w3-orange" (click)="edit(nameInput)"><i class="fa fa-pencil"></i></button> <span *ngIf="editable"> <input class="name" #nameInput (keyup)="onKey(nameInput.value)" (keypress)="inputEnter($event)" [value]="artist.name"> <button class="w3-button w3-green btn-save" (click)="save()">Save</button> </span> <span *ngIf="!editable"> {{artist.name}} </span> `,styleUrls: ['./artist-list-item.component.scss'] }) export class ArtistListItemComponent implements OnInit,AfterViewInit { @Input() artist: any; @Output() onDelete = new EventEmitter(); @Output() onEdit = new EventEmitter(); @Output() onSave = new EventEmitter(); @ViewChild('nameInput') nameInput; public editable: boolean = false; name: any = ''; constructor(private Data: DataService,private rd: Renderer2) { } ngAfterViewInit() { console.log(this.nameInput); } ngOnInit() { } edit(el) { console.log(el); console.log(this.nameInput); this.editable = true; this.name = this.artist.name; } }
edit(el) { console.log(el); console.log(this.nameInput); this.nameInput.focus(); this.editable = true; this.name = this.artist.name; }
根据您的代码,只有当editable为true时,nameInput才会出现.此处,您可以将editable的默认值设置为false(public editable:boolean = false).所以元素甚至不存在于DOM中,这就是为什么即使你在ngAfterViewInit中调用它也会给你未定义的原因.
原文链接:https://www.f2er.com/angularjs/140963.html<span *ngIf="editable"> <input class="name" #nameInput (keyup)="onKey(nameInput.value)" (keypress)="inputEnter($event)" [value]="artist.name"> <button class="w3-button w3-green btn-save" (click)="save()">Save</button> </span>