Angular -获取所有选定的下拉值，并使用ElementRef指定自定义css类

<select [(ngModel)]="selectedValues" multiple>
  <option value="value1">Value 1</option>
  <option value="value2">Value 2</option>
  <option value="value3">Value 3</option>
</select>

import { Component, ElementRef } from '@angular/core';

@Component({
  selector: 'app-my-component',
  templateUrl: './my-component.component.html',
  styleUrls: ['./my-component.component.css']
})
export class MyComponent {
  selectedValues: string[];
  
  constructor(private elementRef: ElementRef) { }
  
  getSelectedValues() {
    const selectElement = this.elementRef.nativeElement.querySelector('select');
    const selectedOptions = Array.from(selectElement.selectedOptions);
    const selectedValues = selectedOptions.map(option => option.value);
    return selectedValues;
  }
}