将传递值发送到 Angular 2 组件

Question

我正在尝试将一个简单的字符串传递到 angular 2 组件中。对于我的生活，我找不到问题。我将值作为组件上的硬编码值从 index.html

传递

<html>
  <head>
    <title>Angular 2 QuickStart</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="styles.css">

    <!-- 1. Load libraries -->
     <!-- Polyfill(s) for older browsers -->
    <script src="node_modules/es6-shim/es6-shim.min.js"></script>

    <script src="node_modules/zone.js/dist/zone.js"></script>
    <script src="node_modules/reflect-metadata/Reflect.js"></script>
    <script src="node_modules/systemjs/dist/system.src.js"></script>

    <!-- 2. Configure SystemJS -->
    <script src="systemjs.config.js"></script>
    <script>
      System.import('app').catch(function(err){ console.error(err);  });
    </script>
  </head>

  <!-- 3. Display the application -->
  <body>


    <accordian [inputField]="'string'">Loading...</accordian>


  </body>
</html>

组件

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

@Component({
  selector: 'accordian',
  templateUrl: 'app/accordian.html',
  styleUrls:  ['app/accordian.css']
})
export class Accordian {
  @Input() inputField;
  expanded = true;
  expandToggle(){
    console.log(this.inputField)
    this.expanded = !this.expanded;
  }
}

模板

<header (click)="expandToggle($event)">
  <h4>Select an Activity!!!</h4>
  <button>{{expanded ? '-' : '+'}}</button>
</header>
<ul *ngIf="expanded">
  <li>
      <h5>{{inputField}}</h5>
      <a href="#">Update Personal Information</a>
  </li>
  <li>
      <h5>User Tools</h5>
      <a href="#">Update Personal Information</a>
  </li>
  <li>
      <h5>User Tools</h5>
      <a href="#">Update Personal Information</a>
  </li>
</ul>

当我点击加号按钮吐出值时，我得到的都是未定义的。任何帮助都会很棒！

Answer 1

我不确定您是否可以从 index.html

执行此操作

通常要使用 Components（或 Directives），您需要使用 @Component 或 [= 将它们指定为指令12=] 装饰器。

我应该从 QuickStart 的标准 AppComponent 方法开始，并在 AppComponent 中使用 Accordian。

希望对您有所帮助。

Answer 2

这是link工作 plunker code

Index.html

<!DOCTYPE html>
<html>

  <head>
    <title>angular2 playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://code.angularjs.org/2.0.0-beta.17/angular2-polyfills.js"></script>
    <script src="https://code.angularjs.org/tools/system.js"></script>
    <script src="https://code.angularjs.org/tools/typescript.js"></script>
    <script src="config.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  </head>

  <body>
    <my-app>
    loading...
  </my-app>
  </body>

</html>

main.ts

import {bootstrap} from '@angular/platform-browser-dynamic';
import {App} from './app';

bootstrap(App, [])
  .catch(err => console.error(err));

app.ts

import {Component} from '@angular/core';
import {Accordian} from './accordian';

@Component({
  selector: 'my-app',
  providers: [],
  template: `
    <div>
      <accordian [inputField]='"string"'></accordian>
    </div>
  `,
  directives: [Accordian]
})
export class App {
  constructor() {
    this.name = 'Angular2 (Release Candidate!)'
  }
}

accordian.ts

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

@Component({
  selector: 'accordian',
  providers: [],
  template: `
    <header (click)="expandToggle($event)">
      <h4>Select an Activity!!!</h4>
      <button>{{expanded ? '-' : '+'}}</button>
    </header>
    <ul *ngIf="expanded">
      <li>
          <h5>{{inputField}}</h5>
          <a href="#">Update Personal Information</a>
      </li>
      <li>
          <h5>User Tools</h5>
          <a href="#">Update Personal Information</a>
      </li>
      <li>
          <h5>User Tools</h5>
          <a href="#">Update Personal Information</a>
      </li>
    </ul>
  `,
  directives: []
})
export class Accordian {
  @Input() inputField: string;
  expanded = true;

  expandToggle(){
    console.log(this.inputField)
    this.expanded = !this.expanded;
  }

}

Answer 3

Angular 仅在其他组件内不对 index.html 进行任何绑定。

在根组件中获取属性值的解决方法是

export class AppComponent {
  constructor(elementRef:ElementRef) {
    console.log(elementRef.nativeElement.getAttribute('inputField));
  }
}

另见 https://github.com/angular/angular/issues/1858

将传递值发送到 Angular 2 组件

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