通过获取,我从服务器获得JWT。收到此 JWT,因为当我执行控制台.log(resData.token(时,令牌显示在控制台中。但是我无法将令牌保存在异步存储中。回应是这样的:
{"_40": 0, "_55": 空, "_65": 0, "_72": 空}
我认为当 asynstorage.setItem 运行时,获取尚未完成,但我如何等待它首先完成?
import React, { useState } from 'react';
import { Text, TextInput, Button, SafeAreaView } from 'react-native';
import AsyncStorage from '@react-native-community/async-storage';
const SignInScreen = props => {
const [username, setUsername] = useState('');
const [password, setPassword] = useState('');
const SignInHandler = async () => {
const req = await fetch('http://localhost:8080/auth/signin', {
method: 'POST',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json'
},
body: JSON.stringify({username: username, password: password})
});
const res = await req;
if (res.ok) {
const resData = await res.json();
console.log(resData.token); // this works!
await AsyncStorage.setItem('token', JSON.stringify(resData.token));
console.log(AsyncStorage.getItem('token')); // this does not work
} else {
console.log('no user found');
};
};
return (
<SafeAreaView>
<Text>Username</Text>
<TextInput value={username} onChangeText={username => setUsername(username)} />
<Text>Password</Text>
<TextInput value={password} onChangeText={password => setPassword(password)} />
<Button title="Sign In" onPress={SignInHandler} />
</SafeAreaView>
);
};
SignInScreen.navigationOptions = navigation => ({
headerShown: false
});
export default SignInScreen;
AsyncStorage 中的方法都是异步的。你可以这样使用它:
console.log(await AsyncStorage.getItem('token'));
您可以在文档中找到更多信息
{"_40": 0, "_55": null, "_65": 0, "_72": null}
这意味着承诺没有解决。 异步存储返回我们必须解决的承诺值。
尝试使用异步 - 等待函数来解决此问题。
await AsyncStorage.setItem('token', JSON.stringify(resData.token));
console.log(await AsyncStorage.getItem('token'));
这将解决问题