angular - 如何以 Angular 从一个组件打开模态到另一个组件？

Question

我创建模态模态组件并在 modal.component.html 文件中编码我的模态。我想在我的 header.component.html 文件中的 header 组件中使用这个模式。

我的 header.component.html 的相关部分如下:

<div style="text-align: center">
  <a class="social-account-profile icon-plus"
     (click)="onButtonClick()"</a>
</div>

onButtonClick是我的 header.component.ts 中的一个方法，如下所示:

export class HeaderComponent implements OnInit {

  constructor(public router: Router, public authService: AuthService,
              public appGlobal: AppGlobals, public  modal: ModalComponent) {
  }

  ngOnInit() {
  }

  onButtonClick() {
    this.modal.openModal();
  }

} 

openModal在我的 modal.component.ts 文件中的方法如下:

export class ModalComponent implements OnInit {

  @ViewChild('projctModal') projctModal: any;
  openModal() {
    this.projctModal.show();
  }

  constructor(private formvalidation: FormValidation) {
  }

  ngOnInit() {
  }

}

我的 modal.component.html 文件如下:

<div mdbModal #projctModal="mdbModal" class="modal fade top " id="projctModal" tabindex="-1" role="dialog"
     aria-labelledby="myModalLabel"
     aria-hidden="true">
</div>

当我运行代码时，我在 chrome 控制台中收到此错误:

ERROR TypeError: Cannot read property 'show' of undefined

我怎样才能解决这个问题 ？

Answer 1

您需要创建一个模态服务以使其在下面的示例示例中工作。

模态组件

import { Component, ElementRef, Input, OnInit,ViewChild, OnDestroy } from '@angular/core';
import {ModalService} from './modal.service';

@Component({
  selector: 'app-modal',
  templateUrl: './modal.component.html'
})
export class ModalComponent implements OnInit, OnDestroy {
  @Input() id: string;
    private element: any;
     @ViewChild('basicModal') basicModal: ElementRef;


    constructor(private modalService: ModalService, private el: ElementRef) {
        this.element = el.nativeElement;
    }

    ngOnInit(): void {
        let modal = this;

        // ensure id attribute exists
        if (!this.id) {
            console.error('modal must have an id');
            return;
        }
        // add self (this modal instance) to the modal service so it's accessible from controllers
        this.modalService.add(this);
    }

    // remove self from modal service when directive is destroyed
    ngOnDestroy(): void {
        this.modalService.remove(this.id);
        this.element.remove();
    }

    // open modal
    open(): void {
        this.basicModal.show();
    }

    // close modal
    close(): void {
        this.basicModal.hide()
    }


}

它是 html

<div mdbModal #basicModal="mdbModal" class="modal fade right" tabindex="-1" role="dialog" aria-labelledby="myBasicModalLabel"
  aria-hidden="true">
  <div class="modal-dialog modal-full-height modal-right" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h4 class="modal-title w-100" id="myModalLabel">Modal title</h4>

        <button type="button" class="close pull-right" aria-label="Close" (click)="basicModal.hide()">
          <span aria-hidden="true">×</span>
        </button>
       </div>
      <div class="modal-body">
         <ng-content></ng-content>
      </div>
      <div class="modal-footer">
        <button type="button" mdbBtn color="secondary" class="waves-light" aria-label="Close" (click)="basicModal.hide()" mdbWavesEffect>Close</button>
        <button type="button" mdbBtn color="primary" class="relative waves-light" mdbWavesEffect>Save!</button>
      </div>
    </div>
  </div>
</div>

模态服务代码如下

import { Injectable } from '@angular/core';

@Injectable()
export class ModalService {

  private modals: any[] = [];

     add(modal: any) {
        this.modals.push(modal);
    }

    remove(id: string) {
        this.modals = this.modals.filter(x => x.id !== id);
    }

    open(id: string) {
        let modal: any = this.modals.filter(x => x.id === id)[0];
        modal.open();
    }

    close(id: string) {
        let modal: any = this.modals.filter(x => x.id === id)[0];
        modal.close();
    }

}

并且在您的实际组件中像这样使用它

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

import {ModalService} from './modal/modal.service';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
   private bodyText: string;

    constructor(private modalService: ModalService) {
    }

    ngOnInit() {
        this.bodyText = 'This text can be updated in modal 1';
    }

    openModal(id: string) {
        this.modalService.open(id);
    }

    closeModal(id: string) {
        this.modalService.close(id);
    }


}

和它的 html

<div class="col-md-6 col-md-offset-3">
    <h1>Home</h1>
    <p>{{bodyText}}</p>
    <button (click)="openModal('custom-modal-1')">Open Modal 1</button>
    <button (click)="openModal('custom-modal-2')">Open Modal 2</button>

</div>


<app-modal id="custom-modal-1">
    <h1>A Custom Modal!</h1>
    <p>Home page text: <input type="text" [(ngModel)]="bodyText" /></p>
    <button (click)="closeModal('custom-modal-1');">Close</button>
</app-modal>

<app-modal id="custom-modal-2">
    <h1>A Custom Modal!</h1>

</app-modal>