reactjs - React 应用程序不显示从 MongoDB Atlas 获取的数据
问题描述
我正在创建一个从 MongoDb Atlas 获取数据的简单 Web 应用程序(MERN 堆栈)。我有两个组件,一个称为列表(列表项数组),另一个称为列表项:
Listings.js 组件:
import React, { Fragment, useContext, useEffect } from "react";
import ListingItem from "./ListingItem";
import ListingContext from "../../context/listing/listingContext";
const Listings = () => {
const listingContext = useContext(ListingContext);
const { listings, getListings, loading } = listingContext;
useEffect(() => {
getListings();
// eslint-disable-next-line
}, []);
return (
<Fragment>
{listings.map((listing) => (
<ListingItem key={listing._id} listing={listing} />
))}
</Fragment>
);
};
export default Listings;
ListingItem.js 组件:
import React from "react";
import { makeStyles } from "@material-ui/core/styles";
import PropTypes from "prop-types";
import Card from "@material-ui/core/Card";
import CardHeader from "@material-ui/core/CardHeader";
import CardMedia from "@material-ui/core/CardMedia";
import CardContent from "@material-ui/core/CardContent";
import CardActions from "@material-ui/core/CardActions";
import Avatar from "@material-ui/core/Avatar";
import Typography from "@material-ui/core/Typography";
import IconButton from "@material-ui/core/IconButton";
import FavoriteIcon from "@material-ui/icons/Favorite";
import ShareIcon from "@material-ui/icons/Share";
import listingImage from "../../resources/listing.jpg";
const useStyles = makeStyles(() => ({
root: {
maxWidth: 345,
},
media: {
height: 0,
paddingTop: "56.25%", // 16:9
},
avatar: {
backgroundColor: "coral",
},
}));
const ListingItem = (listing) => {
const classes = useStyles();
const { neighbourhood, bedrooms, price, priceCurr, area, areaUoM } = listing;
return (
<div className="container">
<div className="listing-item">
<Card className={classes.root}>
<CardHeader
avatar={<Avatar className={classes.avatar} />}
title="Title"
subheader="Subtitle"
/>
<CardMedia className={classes.media} image={listingImage} title="" />
<CardContent>
<Typography component="p">
{price} {priceCurr}
</Typography>
<Typography component="p">A {bedrooms} bedroom,</Typography>
<Typography component="p">
{area} {areaUoM} apartment
</Typography>
<Typography component="p">Located in {neighbourhood}</Typography>
</CardContent>
<CardActions disableSpacing>
<IconButton aria-label="add to favorites">
<FavoriteIcon />
</IconButton>
<IconButton aria-label="share">
<ShareIcon />
</IconButton>
</CardActions>
</Card>
</div>
</div>
);
};
ListingItem.propTypes = {
listing: PropTypes.object.isRequired,
};
export default ListingItem;
该应用程序显然已连接到 Mongodb Atlas,因为当我运行该应用程序时,它恰好将两个列表项呈现到屏幕上(我在数据库中有两个文档)。但它没有显示我在 ListingItem 组件中拥有的变量 {price}、{priceCurr}、{bedrooms} 和 {neighbourhood}。
有没有人遇到过同样的问题?
解决方案
我认为您对道具进行了错误的解构。
<ListingItem key={listing._id} listing={listing} />
const ListingItem = ({listing}) => {
将你的道具包裹在一个{}
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