我正在创建聊天体验,并且页面通过使用 ionic-angular 上的 Content 中的 scrollToBottom 方法来跟上对话。如果我从“PreChat.html”开始并转到“Chat.html”,然后我关闭“Chat.html”以返回“PreChat.html”并再次返回“Chat.html”,我会收到以下错误: “无法读取 null 的属性‘scrollToBottom’”。经验应该可以随时输入或重复输入。

PreChat.html:

<ion-content>
  <button (click)="goToChat()" href="#">
    Chat
  </button>
</ion-content>

PreChat.ts:
import { Component } from '@angular/core';
import { ModalController } from 'ionic-angular';
import { Chat } from '../chat';

@Component({
  selector: 'preChat',
  templateUrl: 'preChat.html'
})
export class PreChat  {
   constructor(private modalCtrl: ModalController){}

   goToChat(): any {
    let profileModal = this.modalCtrl.create(Chat);
    profileModal.present();
  }
}

聊天.html:
<ion-content>
  <button ion-button="filter-button"(click)="dismiss()">
    <ion-icon name="close"></ion-icon>
  </button>
  <div *ngFor="let convo of conversationArray">
    <div class="b-text">{{convo.speak}}</div>
  </div>
</ion-content>

聊天记录:
import { Component, ViewChild } from '@angular/core';
import { Content, Events, ViewController } from 'ionic-angular';

@Component({
  templateUrl: 'Chat.html'
})

export class Chat {
  @ViewChild(Content) content: Content;
  conversationArray: any[] = [];
  constructor(private events: Events, private viewCtrl: ViewController){
    this.events.subscribe('conversation', convo => {
      this.conversationArray = convo;
      this.content.scrollToBottom();
    })
  }
  dismiss() {
   this.viewCtrl.dismiss();
 }
}

最佳答案

为此,您必须使用 ionViewDidEnter 页面事件而不是 constructor


ionViewDidEnter() : void {
 this.platform.ready().then(() => { //platform ready
   this.events.subscribe('conversation', convo => {
      this.conversationArray = convo;
      this.content.scrollToBottom();
    })
 })
}

关于javascript - ionic 2 : How do you reinstantiate @ViewChild if you dismiss the view?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/43511090/

10-16 19:42
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