Question

案例如下：我有一个ion-tabs容器，其中包含多个ion-tab元素，以及登录我的应用程序的不同用户。我需要做的是根据记录的用户类型显示或隐藏ion-tab元素。

问题是我需要动态地执行此操作，如果我使用[show]="variable"之类的指令，则它不起作用。

tabs.ts

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

import { Page1 } from '../page1/page1';
import { Page2 } from '../page2/page2';

@Component({
  templateUrl: 'tabs.html'
})
export class TabsPage {
  // this tells the tabs component which Pages
  // should be each tab's root Page
  tab1Root: any;
  tab2Root: any;
  tab3Root: any;
  tab4Root: any;
  tab5Root: any;
  variable: any;

  constructor(public userData: UserData) {
   // get variable from local storage
    this.userData.getUser().then((value) => {
      if(value.typeLabel == 'Expert') {
        this.variable = true;
        console.log('1->',value.typeLabel);
      }else if(value.typeLabel == 'Client'){
        this.variable = false;
        console.log('2->',value.typeLabel);
      }
    });

    this.tab1Root = this.variable?Page1:Page2; <-- i want to show specify tabs depending on variable value
    this.tab2Root = NotificationsPage;
    this.tab3Root = MessagesPage;
    this.tab4Root = InstructionsPage;
    this.tab5Root = ExpertsPage;
  }
}

tabs.html

<ion-tabs>
  <ion-tab [root]="tab1Root" tabTitle="Home" tabIcon="home"></ion-tab>
  <ion-tab [root]="tab2Root" tabTitle="tab_title" tabIcon="notifications"></ion-tab>
  <ion-tab [root]="tab3Root" tabTitle="tab_title" tabIcon="home"></ion-tab>
  <ion-tab [root]="tab4Root" tabTitle="tab_title" tabIcon="home"></ion-tab>
  <ion-tab [root]="tab5Root" tabTitle="tab_title" tabIcon="home"></ion-tab>
</ion-tabs>

但始终this.tab1Root返回Page1;

我做错了什么？有人可以帮助我吗？

Answer 1

尝试使用*ngIf

<ion-tabs *ngIf = "variable">
  <ion-tab [root]="tab1Root" tabTitle="Home" tabIcon="home"></ion-tab>
  <ion-tab [root]="tab2Root" tabTitle="tab_title" tabIcon="notifications"></ion-tab>
  <ion-tab [root]="tab3Root" tabTitle="tab_title" tabIcon="home"></ion-tab>
  <ion-tab [root]="tab4Root" tabTitle="tab_title" tabIcon="home"></ion-tab>
  <ion-tab [root]="tab5Root" tabTitle="tab_title" tabIcon="home"></ion-tab>
</ion-tabs>

在您的.ts文件中

使变量variable = true显示标签，使false不显示标签。

Answer 2

在组件中创建一个tabs数组，并使用它来动态加载模板。然后，您可以轻松地操作组件中的tabs数组：

<强> tabs.ts

content = response.query.pages.<page number>.extract

<强> tabs.html

import { Page1 } from '../page1/page1';
import { Page2 } from '../page2/page2';

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

  tabs: any[] = [
    { title: "Home", root: Page2, icon: "home" },
    { title: "tab_title", root: NotificationsPage, icon: "notifications" },
    { title: "tab_title", root: MessagesPage, icon: "home" },
    { title: "tab_title", root: InstructionsPage, icon: "home" },
    { title: "tab_title", root: ExpertsPage, icon: "home" }
  ];

  constructor(public userData: UserData) {
    // get variable from local storage
    this.userData.getUser().then((value) => {
      if(value.typeLabel == 'Expert') {
        this.tabs[0].root = Page1;
        console.log('1->',value.typeLabel);
      } else if(value.typeLabel == 'Client'){
        this.tabs[0].root = Page2;
        console.log('2->',value.typeLabel);
      }
    });
  }
}

Answer 3

不是将变量值设置为tab1Root，而是将其设置为函数，以便每次到达变量时执行它。

this.tab1Root = () => this.variable?Page1:Page2;

Answer 4

我在离子论坛上回答：它不会起作用。这就是Ionic的构建方式，它目前不允许动态设置选项卡根页面。我不得不破解了几个小时，最后通过以下方式让它工作： 1）获取选项卡组件的引用以及要动态设置的选项卡的引用。不要为此动态选项卡设置[root]属性，因为Ionic将运行一个方法，该方法不允许您稍后更新此选项卡的根页。

<ion-tabs #appTabs>
  <ion-tab #tabA tabTitle="Tab A" tabIcon="list-box"></ion-tab>
  <ion-tab [root]="tab2Root" tabTitle="Tab B" tabIcon="albums"></ion-tab>
  <ion-tab [root]="tab3Root" tabTitle="Tab C" tabIcon="pulse"></ion-tab>
  <ion-tab [root]="tab4Root" tabTitle="Tab D" tabIcon="more"></ion-tab>
</ion-tabs>

2）在TabsPage文件中：

import { Component, ViewChild } from '@angular/core';
import { Store } from '@ngrx/store'; // I'm using ngrx
import { Tabs, Tab } from 'ionic-angular';
import { Observable } from 'rxjs/Observable';
import 'rxjs/operator/filter';
import 'rxjs/operator/map';

import { TabA1Page } from '...';
import { TabA2Page } from '...';
import { TabBPage } from '...';
import { TabCPage } from '...';
import { TabDPage } from '...';
import { AppState } from '../../app.reducer';
import { DashboardCard } from '...';

@Component({
  templateUrl: 'tabs.page.html',
  selector: 'page-tabs'
})
export class TabsPage {
  public tab1Root: any; // As you can see, it's not set yet.
  public tab2Root: any = TabBPage;
  public tab3Root: any = TabCPage;
  public tab4Root: any = TabDPage;

  // Get the references
  @ViewChild('appTabs') private tabsRef: Tabs;
  @ViewChild('tabA') private tabRef: Tab;

  constructor(private store: Store<AppState>) {}

  public ionViewDidEnter() {
    // These three sources can change the root page for the tab A:
    const defaultDashboard$ = this.store.select('task', 'fetchDashboardCards', 'value');
    const dashboardByProject$ = this.store.select('task', 'fetchDashboardCardsByProject', 'value');
    const dashboardByDueDate$ = this.store.select('task', 'fetchDashboardCardsByDueDate', 'value');

    Observable
      .merge(defaultDashboard$, dashboardByProject$, dashboardByDueDate$)
      .filter(v => v != null)
      .map((dashboard: DashboardCard[]) => dashboard[0].layout === 'project' ? TabA1 : TabA2)
      .distinctUntilChanged()
      .subscribe(this.setTabARootPage.bind(this));
  }

  private setTabARootPage(rootPage) {
    // This is the hack

    // set the root property that we didn't set in the view as [root]="..."
    this.tabRef.root = rootPage;

    /*
    * Modifying private attributes to make it work.
    * This will allow Ionic to run the "tabsInstance.load()" method to load a new root page
    * It also allows us to select the same tab again.
    */
    this.tabRef._loaded = false;
    this.tabsRef._tabs[0].isSelected = false;

    this.tabsRef.select(this.tabRef); // select the tab again
  }

}

Answer 5

现在：

IonicModule.forRoot(MyApp, {
  tabsHideOnSubPages: true
})

我如何隐藏和有条件地显示标签 - 离子2？

5 个答案: