angular 2 input decorator why it need?

Question

我研究了Angular 2.我面临着将数据传输到父组件的组件的任务。在官方文档中编写时使用@输入。否，但我不明白为什么angular 2的开发人员需要它。为什么没有@ INPUT不会进行传输，为什么要添加@Input？

Answer 1

To define an input for a component, use the @Input decorator.

For example component needs a user argument to render information about that user:

<user-profile [user]="currentUser"></user-profile>

So, you need to add an @Input binding to user:

import { Component, Input } from '@angular/core';

@Component({
  selector: 'user-profile',
  template: '<div>{{user.name}}</div>'
})
export class UserProfile {
  @Input() user;
  constructor() {}
}

Answer 2

Bindings in components template like [inputProp]="someValue" are only allowed for @Input() inputProp; or native properties of HTML elements with matching names.

I'm only guessing but 2 explanations come to my mind

• more efficient code or code generation If properties need to be made explicit, this allows more efficient code

• better support for tools This allows tools to check for errors in your code, provide autocompletion when writing templates, and probably more