angular - 错误类型错误 : Cannot read property 'createText' of null in ngx-bootstrap with angular 6

Question

我想在 Angular 6 中使用 @ViewChild 从不同的组件打开 ngx-bootstrap 模式，但我收到了这个错误。

ERROR TypeError: Cannot read property 'createText' of null at ComponentLoader.push../node_modules/ngx-bootstrap/component-loader/component-loader.class.js.ComponentLoader._getContentRef

并且在Inspect Element中这个标签也是可见的

<bs-modal-backdrop class="modal-backdrop fade in"></bs-modal-backdrop>  

Answer 1

您可以使用选择器在 View 中调用模态上的其他组件并使用

• @Input() 在被调用组件中发送数据
• @Output() EventEmitter 从被调用组件返回数据
• OnChanges 绑定(bind)被调用组件的变化

像下面的例子

这是第一个组件:

import { Component, TemplateRef } from '@angular/core';
import { BsModalService, BsModalRef } from 'ngx-bootstrap/modal';

@Component({
  selector: 'demo-modal-service-static',
  templateUrl: './service-template.html'
})
export class DemoModalServiceStaticComponent {
  modalRef: BsModalRef;
  constructor(private modalService: BsModalService) {}

  openModal(template: TemplateRef<any>) {
    this.modalRef = this.modalService.show(template);
  }

  // Use change happen after modal
  public callAfterAdd(modifiedProduct){
  // close this.modalRef
  }
}

这是在 Modal 中调用的另一个组件:

import { Component, TemplateRef , OnInit, OnChanges, Input, Output, EventEmitter, SimpleChanges} from '@angular/core';
import { BsModalService, BsModalRef } from 'ngx-bootstrap/modal';

@Component({
  selector: 'app-product',
  templateUrl: './app-product.html' // put what you want in  view
})
export class AppProductComponent implements OnInit, OnChanges {
  @Input() product : any;
  @Output() afterAdd = new EventEmitter<any>();
  public id: number;
  constructor(private modalService: BsModalService) {}

  ngOnInit() {
  }

  public ngOnChanges (changes: SimpleChanges) {
    console.log(this.product);// see product here
    this.id = changes.product.currentValue.id;
    if(this.id){
        // see here if some change occur in the first component
    }
  }
  /**
  *This function returns the modified product in DemoModalServiceStaticComponent => callAfterAdd
  */
  someOtherFunction(){
  //change something in product 
    //then send the modified data to the 
    this.afterAdd.emit (this.product);
  }
}

这是第一个组件的 View :

<button type="button" class="btn btn-primary" (click)="openModal(template)">Create template modal</button>

<ng-template #template>
  <div class="modal-header">
    <h4 class="modal-title pull-left">Modal</h4>
    <button type="button" class="close pull-right" aria-label="Close" (click)="modalRef.hide()">
      <span aria-hidden="true">&times;</span>
    </button>
  </div>
  <div class="modal-body">
    <app-product [product]=dataTopass (afterAdd)="callAfterAdd(modifiedProduct)"></app-product>
  </div>
</ng-template>