尝试从可观察对象中获取经过过滤的值数组时出现以下错误:
Type 'Observable' must have a 'Symbol.iterator' method that returns an iterator.
代码:
export class ItemsService {
orderItems: OrderItem[] = [];
orderItemsUrl = 'http://localhost:5000/order-items/';
getOrderItemsFromHttp(selectedOrderNumber): Observable<OrderItem[]> {
const tempArr = [];
const orderItems = of (this.http.get<OrderItem[]>(`${this.orderItemsUrl}`)
.subscribe(res => {
this.orderItems = res;
}) );
for (const orderItem of orderItems) { <--- Error here
if (orderItem.orderNumber === selectedOrderNumber) {
tempArr.push(orderItem);
}
}
return of(tempArr);
}
}
如果我修改以下内容
for (const orderItem of orderItems) {
到
for (const orderItem of [orderItems]) {
错误消失了,但是属性 orderNumber 不再被重新识别,并且 intellisens 说:
Property 'orderNumber' does not exist on type 'Subscription'
请问我该如何解决?
最佳答案
在我看来你正在寻找这个:
getOrderItemsFromHttp(selectedOrderNumber): Observable<OrderItem[]> {
return this.http.get<OrderItem[]>(`${this.orderItemsUrl}`).pipe(
map(orderItems => orderItems.filter(oi => oi.orderNuber === selectedOrderNumber))
);
}
为此,您需要导入 map
运算符:
import { map } from 'rxjs/operators';
关于angular - RxJS 6+ 类型 'Observable' 必须有一个返回迭代器的 'Symbol.iterator' 方法,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/61126916/