javascript - 添加/更新元标记在 angular5 中不起作用

Question

我使用下面的代码在运行时在 angular5 中添加或更新元标记

import { Title ,Meta} from '@angular/platform-browser'; 
constructor( private meta:Meta)
 {
 this.meta.addTags([
            {name: 'description', content: 'How to use Angular 4 meta 
       service'},
            {name: 'author', content: 'talkingdotnet'},
            {name: 'keywords', content: 'Angular, Meta Service'}
          ]);
this.meta.updateTag({ name: 'description', content: 'Angular 4 meta service' 
 });
  }

在应用模块中导入元服务

但它不起作用(不在我的页面源代码中)。任何人都可以帮助我

谢谢

Answer 1

你只需要改变:

this.meta.updateTag({ content: 'Angular 4 meta service'} , 'name="description"' );

WORKING DEMO (而不是通过检查元素查看页面源代码检查)原因解释如下

您的方法也 100% 正常工作，您可以在我给定的演示中进行检查。

---

Angular is not served from server side , that's why you can see any meta tags via page view source , any thing that is being changed after page loads that won't be shown in page view source

If you want to check the updated meta tags you need to inspect element and check there

If you want to server side rendering then you can go for Angular Universal