注入来自服务器的CSS变量名(Angular 12)

import { Component, OnInit } from '@angular/core';
import { ServerService } from 'path/to/server.service';
import { Renderer2 } from '@angular/core';

@Component({
  selector: 'app-example',
  templateUrl: './example.component.html',
  styleUrls: ['./example.component.css']
})
export class ExampleComponent implements OnInit {
  cssVariable: string;

  constructor(private serverService: ServerService, private renderer: Renderer2) { }

  ngOnInit() {
    this.serverService.getCSSVariable().subscribe((response: any) => {
      this.cssVariable = response.variableName;
      this.injectCSSVariable();
    });
  }

  injectCSSVariable() {
    const element = document.getElementById('example-element');
    this.renderer.setStyle(element, '--custom-variable', this.cssVariable);
  }
}