离子-菜单活动状态在单击时保持不变

Question

我正在使用Ionic侧面菜单应用程序。 上图突出显示了我的问题。我希望在导航到该特定页面时更改菜单的活动状态。 单击菜单项进行导航，而不单击其他任何地方进行导航时，菜单状态工作正常。

从首页单击“转到列表”时，我正在主页中使用以下代码。

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { ListPage } from '../list/list';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  listPage =  ListPage; 
  constructor(public navCtrl: NavController) {

  }

  goToList(){
    this.navCtrl.setRoot(this.listPage);
  }
}

app.component.ts

import { Component, ViewChild } from '@angular/core';
import { Nav, Platform } from 'ionic-angular';
import { StatusBar } from '@ionic-native/status-bar';
import { SplashScreen } from '@ionic-native/splash-screen';

import { HomePage } from '../pages/home/home';
import { ListPage } from '../pages/list/list';
import { GalleryPage } from '../pages/gallery/gallery';

@Component({
  templateUrl: 'app.html'
})
export class MyApp {
  @ViewChild(Nav) nav: Nav;

  rootPage: any = HomePage;
  activePage: any;

  pages: Array<{title: string, component: any}>;

  constructor(public platform: Platform, public statusBar: StatusBar, public splashScreen: SplashScreen) {
    this.initializeApp();

    // used for an example of ngFor and navigation
    this.pages = [
      { title: 'Home', component: HomePage },
      { title: 'List', component: ListPage },
      { title: 'Gallery', component: GalleryPage}
    ];

    this.activePage = this.pages[0];

  }

  initializeApp() {
    this.platform.ready().then(() => {
      // Okay, so the platform is ready and our plugins are available.
      // Here you can do any higher level native things you might need.
      this.statusBar.styleDefault();
      this.splashScreen.hide();
    });
  }

  openPage(page) {
    // Reset the content nav to have just this page
    // we wouldn't want the back button to show in this scenario
    this.nav.setRoot(page.component);
    this.activePage = page;
  }

  checkActive(page){
    return page === this.activePage;
  }
}

对此有任何帮助吗？

Answer 1

我能够自己找到答案，然后将其发布给其他人以后参考。

在 ngAfterViewInit（）中添加了代码，它似乎可以正常工作。

每次页面状态更改时，都会调用

ngAfterViewInit（），并且 view.instance.constructor.name 会为您提供当前页面的构造函数名称，您可以简单地对其进行比较与菜单数组一起找出要导航到的页面，只需将其设置为活动页面即可。

请参阅下面的完整代码

import { Component, ViewChild } from '@angular/core';
import { Nav, Platform } from 'ionic-angular';
import { StatusBar } from '@ionic-native/status-bar';
import { SplashScreen } from '@ionic-native/splash-screen';

import { HomePage } from '../pages/home/home';
import { ListPage } from '../pages/list/list';
import { GalleryPage } from '../pages/gallery/gallery';

@Component({
  templateUrl: 'app.html'
})
export class MyApp {
  @ViewChild(Nav) nav: Nav;

  rootPage: any = HomePage;
  activePage: any;

  pages: Array<{title: string, component: any, active: boolean}>;

  constructor(public platform: Platform, public statusBar: StatusBar, public splashScreen: SplashScreen) {
    this.initializeApp();

    // used for an example of ngFor and navigation
    this.pages = [
      { title: 'Home', component: HomePage, active: false },
      { title: 'List', component: ListPage, active: false },
      { title: 'Gallery', component: GalleryPage, active: false}
    ];

    this.activePage = this.pages[0];

  }

  ngAfterViewInit(){
    this.nav.viewDidEnter.subscribe((view) => {
      for(let i = 0 ; i < this.pages.length ; i++){
        if(this.pages[i].component.name == view.instance.constructor.name){
           this.activePage = this.pages[i];
           break;
        }
      }
    });
  }

  initializeApp() {
    this.platform.ready().then(() => {
      // Okay, so the platform is ready and our plugins are available.
      // Here you can do any higher level native things you might need.
      this.statusBar.styleDefault();
      this.splashScreen.hide();
    });
  }

  openPage(page) {
    // Reset the content nav to have just this page
    // we wouldn't want the back button to show in this scenario
    this.nav.setRoot(page.component);
    this.activePage = page;
  }

  checkActive(page){
    // console.log(page.title, this.activePage.title, page === this.activePage);
    return page === this.activePage;
  }
}