Angular @ViewChild() 错误 : Expected 2 arguments, 但得到 1

Question

尝试 ViewChild 时出现错误。错误是“未提供‘opts’的参数。”

@ViewChild 都给出了错误。

import { Component, OnInit, ElementRef, ViewChild, Output, EventEmitter } from '@angular/core';
import { Ingredient } from 'src/app/shared/ingredient.model';

@Component({
  selector: 'app-shopping-edit',
  templateUrl: './shopping-edit.component.html',
  styleUrls: ['./shopping-edit.component.css']
})
export class ShoppingEditComponent implements OnInit {

@ViewChild('nameInput') nameInputRef: ElementRef;
@ViewChild('amountInput') amountInputRef: ElementRef;
@Output() ingredientAdded = new EventEmitter<Ingredient>();
  constructor() {}

  ngOnInit() {
  }

  onAddItem() {
    const ingName = this.nameInputRef.nativeElement.value;
    const ingAmount = this.amountInputRef.nativeElement.value;
    const newIngredient = new Ingredient(ingName, ingAmount);
    this.ingredientAdded.emit(newIngredient);
  }

}

ts(11,2): error TS2554: Expected 2 arguments, but got 1.

Answer 1

在 Angular 8 中，ViewChild 有两个参数

 @ViewChild(ChildDirective, {static: false}) Component