Question

我正在使用离子标签。一些选项卡是从数据库（没有图标的那些）生成的

现在，当我添加一个新标签并刷新数组时，我应该得到3个动态标签。取而代之的是我有5个（前2个和前2个带有最新创建的选项卡）尽管数组正确有3个对象。

[对象，对象，对象]

所以这里的相关代码（tabs组件有一个监听标签创建的事件）：

// tabs.ts

import { Component } from '@angular/core';
import { Events } from 'ionic-angular';
import { DatabaseService } from "../../providers/database.service";

import { ItemsPage } from '../items/items';
import { ContactPage } from '../contact/contact';
import { HomePage } from '../home/home';
import { CategoryPage } from '../category/category';

@Component({
  templateUrl: 'tabs.html'
})
export class TabsPage {

  categories: any = [];

  tab1Root = HomePage;
  tab2Root = CategoryPage;
  tab3Root = ItemsPage;
  tab4Root = ContactPage;

  constructor(public databaseService: DatabaseService, public events: Events) {
      this.events.subscribe('category:created', () => {
      this.refreshTabs();
    });
  }

  ngOnInit() {
    this.refreshTabs();
  }

  refreshTabs() {
    this.databaseService.getCategories().then(categories => {
      this.categories = categories;
      console.log(this.categories); // [Object, Object, Object]
    });
  }

}

因此，无论何时我添加或编辑我打电话的标签：

this.events.publish（ '类：创建'）;

tabs.html：

<ion-tab [root]="tab2Root" tabTitle="{{ category.name }}" [rootParams]="category.id" *ngFor="let category of categories"></ion-tab>

知道为什么选项卡上的视图不正确吗？

更新：

似乎使用this.category.push({id: 1, name: 'a category name'})正在工作，但我宁愿刷新整个数组，所以我可以从sql查询中订购我想要的方式。

Subject has been posted on ionic forum as well

Answer 1

尝试手动触发变更检测 -

import { Component, NgZone } from '@angular/core';
import { Events } from 'ionic-angular';
import { DatabaseService } from "../../providers/database.service";

import { ItemsPage } from '../items/items';
import { ContactPage } from '../contact/contact';
import { HomePage } from '../home/home';
import { CategoryPage } from '../category/category';

@Component({
  templateUrl: 'tabs.html'
})
export class TabsPage {

  categories: any = [];

  tab1Root = HomePage;
  tab2Root = CategoryPage;
  tab3Root = ItemsPage;
  tab4Root = ContactPage;

  constructor(public databaseService: DatabaseService, public events: Events, private ngZone: NgZone) {
      this.events.subscribe('category:created', () => {
      this.refreshTabs();
    });
  }

  ngOnInit() {
    this.refreshTabs();
  }

  refreshTabs() {
    this.databaseService.getCategories().then(categories => {
    this.ngZone.run(() => {
      this.categories = categories;
      console.log(this.categories); // [Object, Object, Object]
    });
  });
  }

}

Answer 2

在构造函数中使用它来检测更改并刷新页面。

constructor(private ref: ChangeDetectorRef){}

 refreshTabs() {
    this.databaseService.getCategories().then(categories => {
      this.categories = categories;
      console.log(this.categories); // [Object, Object, Object]
      this.changeDetectorRef.detectChanges();
    });
  });
  }

Answer 3

refreshTabs() {
    this.databaseService.getCategories().then(categories => {
      this.categories = categories;
      this.categories = [...this.categories]
      console.log(this.categories); // [Object, Object, Object]
    });
}

你可以应用这个。

Answer 4

我认为目前解决此问题的最佳方法是这样做：

// Wherever you are calling push, refresh the tabs as well

// Like this: 

yourMethodWhereYouPush() {
  this.category.push({id: 1, name: 'a category name'}); 
  this.refreshTabs(); // Add this line so that once you push it, immediately the tabs will be refreshed with new data;
}

Ionic 2：添加新动态选项卡后刷新选项卡视图

4 个答案: