angular - 当父组件使用 ng-content Angular 时从子组件访问父组件

Question

我正在尝试使用依赖注入(inject)从子组件访问父组件。它有效，我可以访问父级以使用它的方法和属性，但我没有在 Angular 文档上看到这种方法。那么你对这种方法有什么想法吗？我应该使用它吗？

因为父组件使用 ng-content(比如 transclude angularjs)所以我不能使用 EventEmitter @Output 方法。

下面是我的代码:

Wizard.component.ts(父级)

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

@Component({
    selector: 'wizard',
    template: `
        <div>
            <ng-content></ng-content>
            <button>Back</button>
            <button>Next</button>
        </div>
    `
})
export class WizardComponent implements OnInit {
    steps = [];

    constructor() { }

    addStep(step) {
        this.steps.push(step);
    }

    ngOnInit() { }
}

step.component.ts(子)

import { WizardComponent } from './wizard.component';
import { Component, OnInit } from '@angular/core';

@Component({
    selector: 'step',
    template: `
        <div>Step <ng-content></ng-content></div>
    `
})
export class StepComponent implements OnInit {
    constructor(private parent: WizardComponent) { 
        this.parent.addStep(this);
    }

    ngOnInit() { }
}

app.component.html(主应用程序)

<wizard>
    <step>1</step>
    <step>2</step>
    <step>3</step>
</wizard>

期待听到您的意见。谢谢!

Answer 1

父组件->向导组件

@Component({
  selector: 'wizard',
  template: `
    <div>
      <steps [steps]="steps"> </steps>
      <button> Back </button>
      <button> Next </button>
      <button (click)="addStep()"> Add a step </button>
    </div>
  `,
})
export class WizardComponent {
  steps:any[]=new Array();
  constructor() {
    this.steps.push({id:1,name:'abc'});
    this.steps.push({id:2,name:'abc'});
    this.steps.push({id:3,name:'abc'});
  }
  addStep(){
    let count = parseInt(this.steps.count) + 1;
    this.steps.push({id:count,name:'abc'});

  }
}

StepComponent -> 子组件

@Component({
  selector: 'steps',
  template: `
    <div>
      <span *ngFor="let step of steps">
            <label> {{step.id}} </label>
             <div> {{step.name}} </div>
      </span>
    </div>
  `,
})
export class StepsComponent {
  @Input() steps:any[]=new Array();
  constructor() {

  }

}

更新 1:每个步骤中都会出现不同的元素，所以我建议你使用 <ng-content>如下

<div>
     <ng-content select=".step-body"> </ng-content>

</div>

你的向导看起来像

  <table>
    <tr>
        <td>
            <steps>
                <div class="step-body">
                hi hello

                </div>
              </steps>
        </td>
        <td>
            <steps>
                <div class="step-body">
                something else

                </div>
            </steps>
        </td>
    </tr>
    </table>

LIVE DEMO