Question

我有一个例如Pipe的方法，它在下面找到它接收到的值的正方形

模板

<input type = "number" placeholder = "Enter number for which square is to be calculated" [(ngModel)] = "value">
  <p>Squared Number is using pipe Transform  {{value | square}} </p>

组件

value = 2;

自定义管道

import { Pipe,PipeTransform } from '@angular/core';

@Pipe({
    name:'square'
})

export class SquarePipe implements PipeTransform{
  transform(value: number, args?: number[]): number {
    return Math.pow(value, 2);
  }

}

但是当我尝试使用像这样的模板时

它不起作用我需要知道为什么？

<input type = "number" placeholder = "Enter number for which square is to be calculated" #value>
  <p>Squared Number is using pipe Transform  {{value | square}} </p>

Answer 1

我想你想要的是

<p>Squared Number is using pipe Transform  {{value.value | square}} </p>

value单独指的是HTMLInputElement

为什么自定义管道不适用于Angular 2中的本地模板变量

1 个答案: