如何使用角4中的Meta删除标记

我可以在index.html中动态设置标签,角度为4的 Meta概念.但是当我尝试删除tags时,我没有
删除,我怎样才能删除之前添加的标签？

这是我试过的：
设置标签：

import {Meta,MetaDeFinition } from '@angular/platform-browser';
@Component({
  SELEctor: 'app-share-video',templateUrl: './share-video.component.html',})
export class ShareVideoComponent implements OnInit {
constructor(public Metaservic:Meta){}
ngOnInit(){
    const ogtitle: MetaDeFinition   =  { name: 'og@R_859_6964@',content: 'Grace' };
    const ogSitename: MetaDeFinition = { name: 'og:site_name',content: 'My Favourite Albums'};
    const ogUrl: MetaDeFinition = { name: 'og:url',content: 'https://angular.io/docs/ts/latest/api/platform-browser/index/Meta-class.html'};
    const ogdesc: MetaDeFinition = { name: 'og:description',content: 'angular 4 share video description'};
    this.Metaservice.addTag(ogtitlE);
    this.Metaservice.addTag(ogSite@R_450_8313@;
    this.Metaservice.addTag(ogUrl);
    this.Metaservice.addTag(ogdesc);
  }        
ngOnDestroy() {
   this.Metaservice.removeTag("property='og@R_859_6964@'");
   this.Metaservice.removeTag("property='og:site_name'");
   this.Metaservice.removeTag("property='og:url'");
   this.Metaservice.removeTag("property='og:description'");
    }
}

在destroy方法中,我删除了标签,但这些标签没有删除,我该如何删除标签？
紧随其后：meta tags blog

this.Metaservice.removeTag("name='og@R_859_6964@'");
this.Metaservice.removeTag("name='og:site_name'");
this.Metaservice.removeTag("name='og:url'");
this.Metaservice.removeTag("name='og:description'");

this.Metaservice.removeTag("property='og@R_859_6964@'");
this.Metaservice.removeTag("property='og:site_name'");
this.Metaservice.removeTag("property='og:url'");
this.Metaservice.removeTag("property='og:description'");