為什么我的應用程式只顯示加載螢屏？當我運行我的應用程式時，它只加載而不顯示其他螢屏并顯示警告
` WARN Possible Unhandled Promise Rejection (id: 0): TypeError: undefined is
我認為這段代碼有問題
import React, { useEffect } from 'react';
import { View, ActivityIndicator, StyleSheet} from 'react-native';
import { AsyncStorage } from '@react-native-async-storage/async-storage';
import { useDispatch } from 'react-redux';
import Colors from '../constants/Colors';
import * as authActions from '../store/actions/auth';
const StartupScreen = props => {
const dispatch = useDispatch();
useEffect(() => {
const tryLogin = async () => {
const userData = await AsyncStorage.getItem('userData');
if (!userData) {
// props.navigation.navigate('Auth');
dispatch(authActions.setDidTryAutoLogin());
return;
}
const transformedData = JSON.parse(userData);
const { token, user } = transformedData;
// props.navigation.navigate('Shop');
dispatch(authActions.authenticate(user, token));
};
tryLogin();
}, [dispatch])
return (
<View style={styles.screen}>
<ActivityIndicator size="large" color={Colors.primary} />
</View>
);
};
const styles = StyleSheet.create({
screen: {
flex: 1,
justifyContent: 'center',
alignItems: 'center'
}
});
export default StartupScreen;
uj5u.com熱心網友回復：
根據您匯入的檔案是錯誤的。
這個：
import { AsyncStorage } from '@react-native-async-storage/async-storage';
應該
import AsyncStorage from '@react-native-async-storage/async-storage';
基本上，您要做的{AsyncStorage}是匯入名為AsyncStorage. 這就是為什么錯誤說：（
_asyncStorage.AsyncStorage.getItem')提到asyncStorage兩次）并且您需要從包中取出整個物件。
轉載請註明出處，本文鏈接：https://www.uj5u.com/yidong/537123.html
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