TypeError： null 不是对象(评估 'storagedTechs.split')

Question

我得到以下错误:可能未处理的承诺拒绝(id:0:网络请求失败)有时错误id更改为id:3。有人能帮帮我吗?

import React, {useState, useEffect} from 'react';
import { SafeAreaView, StyleSheet, Image, AsyncStorage } from 'react-native';
import SpotList from '../components/SpotList';
import logo from '../assets/logo.png';
export default function List () {
const [techs, setTechs] = useState ([]);

useEffect(() => {
AsyncStorage.getItem('techs')
.then((storagedTechs) => {
const techsArray = storagedTechs.split(',').map(tech => tech.trim())
setTechs(techsArray)
})
},[]);

return (
<SafeAreaView style={styles.container}>
<Image style={styles.logo} source={logo}/>
{techs.map(tech => <SpotList key={tech} tech={tech}/>)}
</SafeAreaView>
)
}
const styles = StyleSheet.create ({
container: {
flex: 1,

},
logo: {
height: 32,
resizeMode: 'contain',
alignSelf:'center',
marginTop: 50
},
})

输出错误

Answer 1

我会尝试在然后块之后添加catch块，如

.then((storagedTechs) => {
const techsArray = storagedTechs.split(',').map(tech => tech.trim())
setTechs(techsArray)
})
.catch(err => {
if (err) console.error(err);
});

这将有助于您进一步调试。