在我的本机应用程序中,我想检查用户以前是否已经登录过,然后必须直接将他重定向到'Home‘,而不必再次向他询问凭据。“Home”组件由侧栏中的注销按钮组成。
我当前的代码可以用于新用户日志记录,但是我仍然无法检查用户是否再次打开应用程序,他的登录令牌应该保持不变,他必须被直接重定向到'Home‘。
这是我的代码:
import React, { Component } from 'react'
import { Text, View, Image, TextInput, TouchableOpacity, ScrollView, AsyncStorage, ToastAndroid } from 'react-native'
import axios from 'axios';
export default class Login extends Component {
constructor(){
super();
this.state = {
username: '',
password: '',
isLoggedIn: false,
loginChecked: false,
}
}
componentDidMount(){
this.getItem('userID');
}
//function to extract storage token. Any name can be given ot it.
async getItem(item){
console.log('method ran login screen');
console.log(this.state.isLoggedIn)
try{
const value = await AsyncStorage.getItem(item);
if(value !== null){
this.setState({
isLoggedIn: true,
loginChecked: true
})
}
else{
this.setState({
isLoggedIn: false,
loginChecked: true
})
}
}
catch(error){
console.log(error)
}
console.log(this.state.isLoggedIn)
}
//function to remove storage token
async removeItem(item){
try{
const value = await AsyncStorage.removeItem(item);
if(value == null){
this.setState({
isLoggedIn: false
})
}
}
catch(error){
//handle errors here
}
}
userLogin = () => {
if(this.state.username != '' && this.state.password != ''){
axios.post('http://bi.servassure.net/api/login', {
username: this.state.username,
password: this.state.password
})
.then(res => {
let userToken = res.data.token;
console.log(res.data);
if(res.data.success){
AsyncStorage.setItem('userID', userToken);
this.setState({
isLoggedIn: true
})
this.props.navigation.navigate('Home');
}
else{
ToastAndroid.showWithGravity(
'Invalid login' ,
ToastAndroid.SHORT,
ToastAndroid.CENTER
);
}
})
.catch(err => {
console.log(err);
});
}
else{
ToastAndroid.showWithGravity(
'Please Enter Credentials' ,
ToastAndroid.SHORT,
ToastAndroid.CENTER
);
}
}
logOut(){
this.removeItem('userID');
}
render() {
return (
<ScrollView>
<View style={{justifyContent:'center', alignItems:'center'}}>
<View style={{marginVertical:20}}>
<Text>
Login to your account
</Text>
</View>
<View>
<TextInput
style={{width: 300, height: 50, borderColor: 'gray', borderWidth: 1, borderRadius: 10, marginVertical: 10}}
onChangeText={(username) => this.setState({username})}
placeholder='username'
autoCapitalize = 'none'
/>
<TextInput
style={{width: 300, height: 50, borderColor: 'gray', borderWidth: 1, borderRadius: 10}}
onChangeText={(password) => this.setState({password})}
placeholder='password'
secureTextEntry={true}
/>
</View>
<View style={{justifyContent: 'center', alignItems: 'center'}}>
<TouchableOpacity
style={{width: 300, height: 50, borderWidth:1, borderRadius: 50, borderColor: 'gray', justifyContent: 'center', alignItems: 'center', marginVertical: 10}}
onPress={this.userLogin}>
<Text>
LOGIN
</Text>
</TouchableOpacity>
<Text>Forget Password</Text>
</View>
</View>
</ScrollView>
)
}
}
另外,我在登录前有一个SplashScreen:
import React, { Component } from 'react'
import { Text, View } from 'react-native'
export default class SplashScreen extends Component {
componentDidMount(){
setTimeout( () => {
this.props.navigation.navigate('Login')
}, 2000)
}
render() {
return (
<View style={styles.viewStyles}>
<Text style={styles.textStyles}> My App </Text>
</View>
)
}
}
const styles = {
viewStyles: {
flex: 1,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: 'orange'
},
textStyles: {
color: 'white',
fontSize: 40,
fontWeight: 'bold'
}
}
我的反应有点本土化,请帮助解决这个问题。
发布于 2019-06-20 13:26:39
在Login.js文件中执行如下操作:
import {AsyncStorage} from react-native;
在获得登录API的响应成功后,您可以这样做:
AsyncStorage.setItem('userID', responsejson.user_detail.userID);
同样,您也可以存储令牌。
AsyncStorage.setItem('token', responsejson.user_detail.token);
然后在您的splashscreen.js,导入AsyncStorage中以与上面相同的方式,然后将这些代码放在componentWillMount()或componentDidMount()中
你的splashscreen.js
var value = AsyncStorage.getItem('token');
value.then((e)=>{
if (e == '' || e == null ){
this.props.navigation.replace('Login')
}else {
this.props.navigation.replace('Home')
}
})
Explanation:加载splashscreen.js时,它将检查异步存储中的令牌,如果它将令牌导航到主屏幕,则导航到Login屏幕。
发布于 2019-06-20 23:47:16
导入库并使用开关导航器。它旨在根据用户的登录状态处理应用程序导航。
https://stackoverflow.com/questions/56686650
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