message: fix(demo): fix scrollTop
diff: -import { Component, Inject, Renderer } from '@angular/core';
  +import { Component, Inject, OnDestroy, Renderer } from '@angular/core';
  import { Router, NavigationEnd } from '@angular/router';
  import { isBs3, setTheme } from 'ngx-bootstrap/utils';
  import { routes } from '../../app.routing';
  import { StyleManager } from '../../theme/style-manager';
  import { ThemeStorage } from '../../theme/theme-storage';
  import { DOCUMENT } from '@angular/platform-browser';
  +import { Subscription } from 'rxjs/Subscription';
  const _bs3Css =
  'assets/css/bootstrap-3.3.7/css/bootstrap.min.css';
  @@ -15,7 +16,7 @@ const _bs4Css =
  selector: 'sidebar',
  templateUrl: './sidebar.component.html'
  })
  -export class SidebarComponent {
  +export class SidebarComponent implements OnDestroy{
  isShown = false;
  get isBs3(): boolean {
  @@ -26,6 +27,7 @@ export class SidebarComponent {
  search: any = {};
  currentTheme: 'bs3' | 'bs4';
  + scrollSubscription: Subscription;
  constructor(
  public styleManager: StyleManager,
  @@ -42,7 +44,7 @@ export class SidebarComponent {
  this.router = router;
  this.routes = this.routes.filter((v: any) => v.path !== '**');
  - this.router.events.subscribe((event: any) => {
  + this.scrollSubscription = this.router.events.subscribe((event: any) => {
  if (event instanceof NavigationEnd) {
  this.toggle(false);
  }
  @@ -58,6 +60,7 @@ export class SidebarComponent {
  this.isShown
  );
  if (this.isShown === false) {
  + this.renderer.setElementProperty(this.document.documentElement, 'scrollTop', 0);
  this.renderer.setElementProperty(this.document.body, 'scrollTop', 0);
  }
  }
  @@ -72,4 +75,8 @@ export class SidebarComponent {
  this._themeStorage.storeTheme(this.currentTheme);
  }
  }
  +
  + ngOnDestroy() {
  + this.scrollSubscription.unsubscribe();
  + }
  }
  