在AngularFirestore中，它只是document.id.但是，要使其正常工作，必须使用snapshotChanges而不是valueChanges.所以:

In AngularFirestore it is simply document.id. But for this to work you must use snapshotChanges instead of valueChanges. So:

orders = this.orderCollection.snapshotChanges();

然后:

<tr *ngFor="let o of orders | async">
    <td>{{o.data().orderName}}</td>
    <td><a (click)="editOrder(o.id)">Edit</a></td>
</tr>

灵感来自: Firestore从集合中获取文档ID 和获取包含文档ID的集合.