如何从ion 4 ion-select中获取选定值

<ion-select [(ngModel)]="selectedValue" (ionChange)="onSelectChange()">
  <ion-select-option value="option1">Option 1</ion-select-option>
  <ion-select-option value="option2">Option 2</ion-select-option>
  <ion-select-option value="option3">Option 3</ion-select-option>
</ion-select>

selectedValue: string;

onSelectChange() {
  console.log(this.selectedValue); // 获取选定的值
}