Question

是否有与$ mdMedia类似的Angular 2服务？我需要根据窗口大小显示或隐藏按钮（如果窗口与屏幕大小相同，我想隐藏它）

Answer 1

也许这可以帮到你。

<强> resize.service.js

import {Injectable} from '@angular/core';
import {BehaviorSubject} from 'rxjs/BehaviorSubject';

@Injectable()
export class ResizeService {
    public window = new BehaviorSubject(null);

    constructor() {
        window.onresize = (e) => {
            this.window.next(e.target);
        };
    }
}

<强> app.component.ts

import {Component} from '@angular/core';
import {ResizeService} from './resize/resize.service';

@Component({
    moduleId: module.id,
    selector: 'my-app',
    templateUrl: 'app.component.html',
    providers: [ResizeService]
})

export class AppComponent {
    constructor(private resizeService: ResizeService) {
        resizeService.window.subscribe((val) => {
            if (val) {
                console.log(val.innerWidth);
            }
        });

    };
}

该服务使用BehaviourSubject。 See this answer描述它是什么。另请参阅https://xgrommx.github.io/rx-book/content/subjects/behavior_subject/index.html

组件订阅BehaviourSubject（窗口）并在屏幕大小更改时获取更新的值。

Answer 2

您可以使用并应使用flex-layout：

官方https://github.com/angular/flex-layout/wiki/Adaptive-Layouts#core-directives--responsive-features

import {ObservableMedia} from '@angular/flex-layout';

@Component({
  selector : 'my-mobile-component',
  template : `
      <div *ngIf="media.isActive('xs')">
         This content is only shown on Mobile devices
      </div>
      <footer>
         Current state: {{ }}
      </footer>
  `
})
export class MyMobileComponent {
  public state = '';
  constructor(public media:ObservableMedia ) {
    media.asObservable()
      .subscribe((change:MediaChange) => {
        this.state = change ? `'${change.mqAlias}' = (${change.mediaQuery})` : ""
      });
  }
}

Angular 2服务 - $ mdMedia

2 个答案: