导入'rxjs/add/operator/map'； 使用 AngularFirestore、AngularFirestoreCollection、AngularFirestoreDocument

Question

构造函数（公共 afs：AngularFirestore）{ this.itemsCollection = this.afs.collection('items', ref => ref.orderBy('title', 'asc'));

this.items = this.itemsCollection.snapshotChanges().map(changes => {
  return changes.map(a => {
    const data = a.payload.doc.data() as Item;
    data.id = a.payload.doc.id;
    return data;
  });
});

} map 无法识别。

Answer 1

您需要使用pipe在可观察流上添加运算符，尝试：

this.items = this.itemsCollection.snapshotChanges().pipe(map(changes => {
  return changes.map(a => {
    const data = a.payload.doc.data() as Item;
    data.id = a.payload.doc.id;
    return data;
  });
}));