类型“Promise<void>”缺少类型中的以下属性答案

【问题标题】：Type 'Promise<void>' is missing the following properties from type类型“Promise<void>”缺少类型中的以下属性
【发布时间】：2020-12-11 07:23:43
【问题描述】：

我不太理解以下错误：

Type 'Promise<void>' is missing the following properties from type 'InventoryModel[]': length, pop, push, concat, and 28 more.  TS2740

我有以下功能组件：

import React, { useEffect, useState } from "react";
import { Grid, TextField } from "@material-ui/core";
import InventoryService from "../services/Inventory";
import InventoryModel from "../Models/Inventory";
import { isThisTypeNode } from "typescript";

type InventoryState = {
  inventoryItems: InventoryModel[];
};

const Inventory: React.FC = () => {
  const [inventory, setInventory] = useState<Partial<InventoryState>>({});
  useEffect(() => {
    const inventoryService = new InventoryService();
    const results = inventoryService.getByLocation().then((response) => {
      setInventory({ ...inventory, inventoryItems: response });
    });
  }, []);
  return <div></div>

“inventoryItems”在这种情况下以红色突出显示。

【问题讨论】：

如果您将(response) 参数更改为(response: InventoryModel[])，编译器可能会给您一个更可操作的错误
感谢您的帮助

标签： reactjs typescript promise

【解决方案1】：

原来我只需要添加 |对 InventoryState 无效。

type InventoryState = {
  inventoryItems: InventoryModel[] | void;
};

【讨论】：