如何解决 react-leaflet 导出错误?
How to resolve the react-leaflet export error?
我想为我的项目在 React js 中渲染地图。因此,为此我使用代码 npm i react-leaflet 安装了 react-leaflet,还在终端中安装了 npm i leaflet 并输入了一些用于 react leaflet 的代码。代码如下:
这是我的 Map.JS 文件:
import React from "react";
import { Map as LeafletMap, TileLayer } from "react-leaflet";
import "./map.css";
// import { showDataOnMap } from "./util";
function Map({ countries, casesType, center, zoom }) {
return (
<div className="map">
<LeafletMap center={center} zoom={zoom}>
<TileLayer
url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
attribution='© <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
/>
</LeafletMap>
</div>
);
}
export default Map;
这是我的 App.js 文件:
import {
Card,
CardContent,
FormControl,
MenuItem,
Select,
} from '@material-ui/core';
import { useEffect, useState } from 'react';
import InfoBox from './InfoBox';
import './App.css';
import Table from './Table';
import { sortData } from './utl';
import LineGraph from './LineGraph';
import MapContainer from './Map';
import "leaflet/dist/leaflet.css";
function App() {
const [countries, setCountries] = useState([]);
const [country, setCountry] = useState('worldwide');
const [countryInfo, setCountryInfo] = useState({});
const [tableData, setTableData] = useState([]);
useEffect(() => {
fetch('https://disease.sh/v3/covid-19/all')
.then((response) => response.json())
.then((data) => {
setCountryInfo(data);
});
}, []);
useEffect(() => {
const getCountriesData = async () => {
await fetch('https://disease.sh/v3/covid-19/countries')
.then((response) => response.json())
.then((data) => {
const countries = data.map((country) => ({
name: country.country,
value: country.countryInfo.iso2,
}));
const sortedData = sortData(data);
setTableData(sortedData);
setCountries(countries);
});
};
getCountriesData();
}, []);
const onCountryChange = async (event) => {
const countryCode = event.target.value;
setCountry(countryCode);
const url =
countryCode === 'worldwide'
? 'https://disease.sh/v3/covid-19/all'
: `https://disease.sh/v3/covid-19/countries/${countryCode}`;
await fetch(url)
.then((response) => response.json())
.then((data) => {
setCountry(countryCode);
// All of the Data... from the country response
setCountryInfo(data);
});
};
console.log('fnfun', countryInfo);
return (
<div className='app'>
<div className='spp_left'>
<div className='app_header'>
<h1>COVID-19 TRACKER</h1>
<FormControl className='app_dropdown'>
<Select
variant='outlined'
value={country}
onChange={onCountryChange}
>
<MenuItem value='worldwide'>Worldwide</MenuItem>
{countries.map((country) => (
<MenuItem value={country.value}>{country.name}</MenuItem>
))}
</Select>
</FormControl>
</div>
<div className='app_stats'>
<InfoBox
title='Coronavirus Cases'
cases={countryInfo.todayCases}
total={countryInfo.cases}
/>
<InfoBox
title='Recovered'
cases={countryInfo.todayRecovered}
total={countryInfo.recovered}
/>
<InfoBox
title='Deaths'
cases={countryInfo.todayDeaths}
total={countryInfo.deaths}
/>
</div>
<MapContainer />
</div>
<Card className='app_right'>
<CardContent>
<h3>Live Cases by Country</h3>
<Table countries={tableData} />
<h3>Worldwide New Cases</h3>
<LineGraph />
</CardContent>
</Card>
</div>
);
}
export default App;
但问题是它显示错误:
Failed to compile ./src/Map.js Attempted import error: 'Map' is not exported from 'react-leaflet' (imported as 'LeafletMap').
此错误发生在构建期间,无法消除。
以下是解决您的问题的步骤:
由于 react-leaflet api 从版本 2.x 更改为 3.x,因此将导入更改为 import { MapContainer as LeafletMap, TileLayer } from "react-leaflet";
。
删除地图组件上的这一行import { showDataOnMap } from './util';
我想为我的项目在 React js 中渲染地图。因此,为此我使用代码 npm i react-leaflet 安装了 react-leaflet,还在终端中安装了 npm i leaflet 并输入了一些用于 react leaflet 的代码。代码如下: 这是我的 Map.JS 文件:
import React from "react";
import { Map as LeafletMap, TileLayer } from "react-leaflet";
import "./map.css";
// import { showDataOnMap } from "./util";
function Map({ countries, casesType, center, zoom }) {
return (
<div className="map">
<LeafletMap center={center} zoom={zoom}>
<TileLayer
url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
attribution='© <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
/>
</LeafletMap>
</div>
);
}
export default Map;
这是我的 App.js 文件:
import {
Card,
CardContent,
FormControl,
MenuItem,
Select,
} from '@material-ui/core';
import { useEffect, useState } from 'react';
import InfoBox from './InfoBox';
import './App.css';
import Table from './Table';
import { sortData } from './utl';
import LineGraph from './LineGraph';
import MapContainer from './Map';
import "leaflet/dist/leaflet.css";
function App() {
const [countries, setCountries] = useState([]);
const [country, setCountry] = useState('worldwide');
const [countryInfo, setCountryInfo] = useState({});
const [tableData, setTableData] = useState([]);
useEffect(() => {
fetch('https://disease.sh/v3/covid-19/all')
.then((response) => response.json())
.then((data) => {
setCountryInfo(data);
});
}, []);
useEffect(() => {
const getCountriesData = async () => {
await fetch('https://disease.sh/v3/covid-19/countries')
.then((response) => response.json())
.then((data) => {
const countries = data.map((country) => ({
name: country.country,
value: country.countryInfo.iso2,
}));
const sortedData = sortData(data);
setTableData(sortedData);
setCountries(countries);
});
};
getCountriesData();
}, []);
const onCountryChange = async (event) => {
const countryCode = event.target.value;
setCountry(countryCode);
const url =
countryCode === 'worldwide'
? 'https://disease.sh/v3/covid-19/all'
: `https://disease.sh/v3/covid-19/countries/${countryCode}`;
await fetch(url)
.then((response) => response.json())
.then((data) => {
setCountry(countryCode);
// All of the Data... from the country response
setCountryInfo(data);
});
};
console.log('fnfun', countryInfo);
return (
<div className='app'>
<div className='spp_left'>
<div className='app_header'>
<h1>COVID-19 TRACKER</h1>
<FormControl className='app_dropdown'>
<Select
variant='outlined'
value={country}
onChange={onCountryChange}
>
<MenuItem value='worldwide'>Worldwide</MenuItem>
{countries.map((country) => (
<MenuItem value={country.value}>{country.name}</MenuItem>
))}
</Select>
</FormControl>
</div>
<div className='app_stats'>
<InfoBox
title='Coronavirus Cases'
cases={countryInfo.todayCases}
total={countryInfo.cases}
/>
<InfoBox
title='Recovered'
cases={countryInfo.todayRecovered}
total={countryInfo.recovered}
/>
<InfoBox
title='Deaths'
cases={countryInfo.todayDeaths}
total={countryInfo.deaths}
/>
</div>
<MapContainer />
</div>
<Card className='app_right'>
<CardContent>
<h3>Live Cases by Country</h3>
<Table countries={tableData} />
<h3>Worldwide New Cases</h3>
<LineGraph />
</CardContent>
</Card>
</div>
);
}
export default App;
但问题是它显示错误:
Failed to compile ./src/Map.js Attempted import error: 'Map' is not exported from 'react-leaflet' (imported as 'LeafletMap').
此错误发生在构建期间,无法消除。
以下是解决您的问题的步骤:
由于 react-leaflet api 从版本 2.x 更改为 3.x,因此将导入更改为
import { MapContainer as LeafletMap, TileLayer } from "react-leaflet";
。删除地图组件上的这一行
import { showDataOnMap } from './util';