在Angular 4 mat-select上未绑定异步值

import { MatSelectModule } from '@angular/material/select';

@NgModule({
  imports: [
    // other imports
    MatSelectModule
  ],
  // other configurations
})
export class AppModule { }

import { Component } from '@angular/core';
import { FormControl } from '@angular/forms';
import { Observable } from 'rxjs';
import { startWith, map } from 'rxjs/operators';

@Component({
  selector: 'app-my-component',
  templateUrl: './my-component.component.html',
  styleUrls: ['./my-component.component.css']
})
export class MyComponent {
  options: string[] = []; // 存储选项值的数组
  myControl = new FormControl();
  filteredOptions: Observable<string[]>;

  constructor() {
    // 异步获取选项值的逻辑，例如从API请求数据
    this.getOptions().subscribe(response => {
      this.options = response;
    });

    // 过滤选项值的逻辑
    this.filteredOptions = this.myControl.valueChanges.pipe(
      startWith(''),
      map(value => this.filterOptions(value))
    );
  }

  getOptions(): Observable<string[]> {
    // 异步获取选项值的实现，例如使用HttpClient发送API请求
    // 返回一个Observable对象，包含异步获取的选项值
  }

  filterOptions(value: string): string[] {
    // 过滤选项值的实现，根据输入的value返回匹配的选项值
  }
}

<mat-form-field>
  <mat-select [formControl]="myControl">
    <mat-option *ngFor="let option of filteredOptions | async" [value]="option">
      {{ option }}
    </mat-option>
  </mat-select>
</mat-form-field>