Javascript 错误:无效的LatLng对象:(54,未定义)
我正在学习react,我是这方面的初学者,我正在尝试使用react的传单工具制作地图。事实上,当我选择一个特定的国家时,我希望它转到所选的国家,但它会生成一个错误,即“错误:无效的LatLng对象:(54,未定义)”,如果您能给我一个解决问题的方法,那将非常有帮助。我有点复杂,非常感谢Javascript 错误:无效的LatLng对象:(54,未定义),javascript,reactjs,react-leaflet,Javascript,Reactjs,React Leaflet,我正在学习react,我是这方面的初学者,我正在尝试使用react的传单工具制作地图。事实上,当我选择一个特定的国家时,我希望它转到所选的国家,但它会生成一个错误,即“错误:无效的LatLng对象:(54,未定义)”,如果您能给我一个解决问题的方法,那将非常有帮助。我有点复杂,非常感谢 import { MenuItem, FormControl, Select, Card, CardContent} from '@material-ui/core'; import React, {useSta
import { MenuItem, FormControl, Select, Card, CardContent} from '@material-ui/core';
import React, {useState, useEffect} from 'react';
import './App.css';
import InfoBox from './InfoBox';
import Map from './Map';
import Table from "./Table";
import { sortData } from "./util";
import LineGraph from "./LineGraph";
import "leaflet/dist/leaflet.css";
function App() {
const [countries, setCountries] = useState([]);
const [country, setCountry] = useState('worldwide');
const [countryInfo, setCountryInfo] = useState({});
const [tableData, setTableData] = useState([]);
const [mapCenter, setMapCenter] = useState({ lat: 34.80746, lng: -40.4796});
const [mapZoom, setMapZoom] = useState(3);
const [mapCountries, setMapCountries] = 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) => ( //ciudades por la API
{
name: country.country, // United States, United Kingdom
value: country.countryInfo.iso2 // UK, USA, FR
}
));
const sortedData = sortData(data);
setTableData(sortedData);
setMapCountries(data);
setCountries(countries); //Cambio de estado por las ciudades de las api
});
};
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);
setCountryInfo(data);
setMapCenter([data.countryInfo.lat, data.countryInfo.lng]);
setMapZoom(4);
});
};
return (
<div className="app">
<div className="app__left">
<div className="app__header">
<h1>COVID 19 TRACKER</h1>
<FormControl className="app__dropdown">
<Select variant="outlined" onChange={onCountryChange} value={country}>
<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>
<Map center={mapCenter} zoom={mapZoom} countries={mapCountries}/>
</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;
从'@material ui/core'导入{MenuItem,FormControl,Select,Card,CardContent};
从“React”导入React,{useState,useffect};
导入“/App.css”;
从“/InfoBox”导入InfoBox;
从“./Map”导入映射;
从“/Table”导入表;
从“/util”导入{sortData};
从“/LineGraph”导入线条图;
导入“传单/目录/传单.css”;
函数App(){
const[countries,setCountries]=useState([]);
const[country,setCountry]=useState(“全球”);
const[countryInfo,setCountryInfo]=useState({});
const[tableData,setTableData]=useState([]);
const[mapCenter,setMapCenter]=useState({lat:34.80746,lng:-40.4796});
const[mapZoom,setMapZoom]=useState(3);
const[mapCountries,setMapCountries]=useState([]);
useffect(()=>{
取回(“https://disease.sh/v3/covid-19/all)然后((response)=>response.json())。然后(data=>{
setCountryInfo(数据);
});
}, []);
useffect(()=>{
const getCountriesData=async()=>{
等待取回(“https://disease.sh/v3/covid-19/countries)然后((响应)=>response.json())。然后((数据)=>{
const countries=data.map((国家)=>(//ciudades por la API
{
名称:country.country,//美国、英国
值:country.countryInfo.iso2//英国、美国、法国
}
));
常数sortedData=sortData(数据);
可设置数据(sortedData);
SETMAP国家(数据);
setCountries(countries);//坎比奥·德·埃斯塔多·波尔·拉斯阿皮市
});
};
getCountriesData();
}, []);
const onCountryChange=异步(事件)=>{
const countryCode=event.target.value;
setCountry(countryCode);
const url=countryCode==“全球”?'https://disease.sh/v3/covid-19/all' : `https://disease.sh/v3/covid-19/countries/${countryCode}`;
等待获取(url)。然后((响应)=>response.json())。然后((数据)=>{
setCountry(countryCode);
setCountryInfo(数据);
setMapCenter([data.countryInfo.lat,data.countryInfo.lng]);
setMapZoom(4);
});
};
返回(
新冠病毒19跟踪器
在全世界
{国家地图((国家)=>(
{country.name}
))}
按国家分列的活病例
全球新病例
);
};
导出默认应用程序;
接下来我将显示我的地图js文件
import React from 'react';
import './Map.css';
import { Map as LeafletMap, TileLayer } from "react-leaflet";
function Map({countries, 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="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors'
/>
</LeafletMap>
</div>
);
}
export default Map;
从“React”导入React;
导入“./Map.css”;
从“react传单”导入{Map as-传单映射,TileLayer};
功能图({国家,中心,缩放}){
返回(
);
}
导出默认地图;
你能用codesandbox或类似的smth制作一个演示来重现这个问题吗?@kboul非常感谢,但我设法解决了我的问题,这是我的写作问题。