使用patchValue动态选择选择框时，对象属性(类型、格式)不呈现

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup } from '@angular/forms';

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

  constructor(private formBuilder: FormBuilder) { }

  ngOnInit() {
    this.myForm = this.formBuilder.group({
      selectControl: ['']
    });
  }

  updateSelectControl(value: string) {
    // 使用setValue方法更新表单控件的值和类型
    this.myForm.get('selectControl').setValue(value);
  }
}