Flutter:如何保持用户登录和注销 [英] Flutter : How to keep user logged in and make logout
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问题描述
我正在获取csrf令牌并在控制台中打印响应数据，但是如何使用响应数据保持用户登录.我正在使用状态代码进行登录，即，如果状态代码为200，则此后移至登录状态.希望让用户保持登录状态，并且仅在用户要注销时才注销
I am getting the csrf token and printing the response data in console but how to keep user logged in using the response data.I am making login using the status code i.e., if status code is 200 then move to login after that I want to keep user logged in and log out only when user wants to log out
我看到了很多例子，但对我来说都没有帮助.
I have seen lot of examples but none are helping in my case.
在我的情况下，我正在使用csrf令牌，但无法使其保持登录状态，并且我也使用了登录表单.
In my case i am using th csrf token and unable to keep it logged in, and i have also used login form.
LoginPage.dart
LoginPage.dart
import 'dart:io';
import 'package:cookie_jar/cookie_jar.dart';
import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:jignasa/home_screen.dart';
import 'package:jignasa/logindata.dart';
import 'package:path_provider/path_provider.dart';
class LoginPage extends StatefulWidget {
static String tag = 'login-page';
@override
_LoginPageState createState() => new _LoginPageState();
}
class _LoginPageState extends State<LoginPage> {
final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
LoginRequestData _loginData = LoginRequestData();
bool _validate = false;
bool _obscureText = true;
var username, password;
@override
Widget build(BuildContext context) {
return Scaffold(
// backgroundColor: Colors.white,
body: SingleChildScrollView(
child: Container(
color: Colors.lightGreen[500],
child: Column(
children: <Widget>[
Center(
child: Container(
width: MediaQuery
.of(context)
.size
.width,
height: MediaQuery
.of(context)
.size
.height / 2.5,
decoration: BoxDecoration(
gradient: LinearGradient(
// begin: Alignment.topCenter,
// end: Alignment.bottomCenter,
colors: [
Color(0xFFFFFFFF),
Color(0xFFFFFFFF),
]
),
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(90)
)
),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Align(
alignment: Alignment.center,
child: Image.asset('images/ic_launcher1.png'),
),
],
),
),
),
Center(
child: SingleChildScrollView(
child: new Form(
key: _formKey,
autovalidate: _validate,
child: _getFormUI(),
),
)
)
],
),
),
),
);
}
Widget _getFormUI() {
return new Column(
children: <Widget>[
SizedBox(height: 24.0),
Center(
child: Text('Login',
style: TextStyle(fontSize: 25,
fontWeight: FontWeight.bold,
color: Colors.white),),
),
new SizedBox(height: 25.0),
new TextFormField(
keyboardType: TextInputType.emailAddress,
autofocus: false,
decoration: InputDecoration(
hintText: 'Username',
contentPadding: EdgeInsets.fromLTRB(20.0, 15.0, 20.0, 15.0),
border:
OutlineInputBorder(borderRadius: BorderRadius.circular(32.0)),
),
validator: _validateName,
onSaved: (value) {
_loginData.username = value;
},
),
new SizedBox(height: 8.0),
new TextFormField(
autofocus: false,
obscureText: _obscureText,
keyboardType: TextInputType.text,
decoration: InputDecoration(
hintText: 'Password',
contentPadding: EdgeInsets.fromLTRB(20.0, 10.0, 20.0, 10.0),
border:
OutlineInputBorder(borderRadius: BorderRadius.circular(24.0)),
suffixIcon: GestureDetector(
child: Icon(
_obscureText ? Icons.visibility : Icons.visibility_off,
semanticLabel:
_obscureText ? 'show password' : 'hide password',
),
),
),
validator: _validatePassword,
onSaved: (String value) {
_loginData.password = value;
}
),
new SizedBox(height: 15.0),
new Padding(
padding: EdgeInsets.symmetric(vertical: 16.0),
child: RaisedButton(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(24),
),
onPressed: () {
_submit();
// Navigator.of(context).pushReplacementNamed('/home');
},
padding: EdgeInsets.all(12),
color: Colors.black54,
child: Text('Log In', style: TextStyle(color: Colors.white)),
),
),
new FlatButton(
child: Text(
'Forgot password?',
style: TextStyle(color: Colors.black54),
),
onPressed: () {},
),
new FlatButton(
onPressed: _sendToRegisterPage,
child: Text('Not a member? Sign up now',
style: TextStyle(color: Colors.black54)),
),
Text(''),
Text(''),
Text(''),
],
);
}
_sendToRegisterPage() {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => HomeScreen()),
);
}
String _validateName(String value) {
if (value.isEmpty) {
return "Username is Required";
} else {
username = value.toString();
}
}
String _validatePassword(String value) {
if (value.isEmpty) {
return "Password is Required";
} else {
password = value.toString();
}
}
_submit() {
if (_formKey.currentState.validate()) {
_formKey.currentState.save();
print("Username ${_loginData.username}");
print("Password ${_loginData.password}");
return SessionId();
} else {
setState(() {
bool _validate = false;
});
}
}
final Dio _dio = Dio();
PersistCookieJar persistentCookies;
final String url = "https://www.xxxx.in/rest/user/login.json";
Future<String> get _localPath async {
final directory = await getApplicationDocumentsDirectory();
print(directory.path);
return directory.path;
}
Future<Directory> get _localCoookieDirectory async {
final path = await _localPath;
final Directory dir = new Directory('$path/cookies');
await dir.create();
print(dir);
return dir;
}
Future<String> getCsrftoken() async{
try {
String csrfTokenValue;
final Directory dir = await _localCoookieDirectory;
final cookiePath = dir.path;
persistentCookies = new PersistCookieJar(dir: '$cookiePath');
persistentCookies.deleteAll(); //clearing any existing cookies for a fresh start
_dio.interceptors.add(
CookieManager(persistentCookies) //this sets up _dio to persist cookies throughout subsequent requests
);
_dio.options = new BaseOptions(
baseUrl: url,
contentType: ContentType.json,
responseType: ResponseType.plain,
// connectTimeout: 5000,
// receiveTimeout: 100000,
headers: {
HttpHeaders.userAgentHeader: "dio",
"Connection": "keep-alive",
},
); //BaseOptions will be persisted throughout subsequent requests made with _dio
_dio.interceptors.add(
InterceptorsWrapper(
onResponse:(Response response) {
List<Cookie> cookies = persistentCookies.loadForRequest(Uri.parse(url));
csrfTokenValue = cookies.firstWhere((c) => c.name == 'csrftoken', orElse: () => null)?.value;
if (csrfTokenValue != null) {
_dio.options.headers['X-CSRF-TOKEN'] = csrfTokenValue; //setting the csrftoken from the response in the headers
}
print(response);
return response;
}
)
);
await _dio.get("https://www.xxxx.in/rest/user/login.json");
print(csrfTokenValue);
return csrfTokenValue;
} catch (error, stacktrace) {
print(error);
// print("Exception occured: $error stackTrace: $stacktrace");
return null;
}
}
SessionId() async {
try {
final csrf = await getCsrftoken();
FormData formData = new FormData.from({
"username": "${_loginData.username}",
"password": "${_loginData.password}",
"csrfmiddlewaretoken" : '$csrf'
});
Options optionData = new Options(
contentType: ContentType.parse("application/json"),
);
Response response = await _dio.post("https://www.xxxx.in/rest/user/login.json", data: formData, options: optionData);
print("StatusCode:${response.statusCode}");
// print(response.data);
if (response.statusCode == 200){
return Navigator.of(context).pushReplacement(MaterialPageRoute(
builder: (context) => HomeScreen(),
));
}
else{
throw Exception();
}
} on DioError catch(e) {
if(e.response != null) {
print( e.response.statusCode.toString() + " " + e.response.statusMessage);
print(e.response.data);
print(e.response.headers);
print(e.response.request);
} else{
print(e.request);
print(e.message);
}
}
catch (error, stacktrace) {
print("Exception occured: $error stackTrace: $stacktrace");
return null;
}
}
}
推荐答案
从api获取响应代码200后，您可以在共享"首选项中进行输入.
You can make an entry in Shared preference after getting response code 200 from api.
SharedPreferences prefs = await SharedPreferences.getInstance();
prefs?.setBool("isLoggedIn", true);
然后您可以在从共享首选项检查状态后导航用户
then you can navigate user after checking status from shared preference
Future<void> main() async {
SharedPreferences prefs = await SharedPreferences.getInstance();
var status = prefs.getBool('isLoggedIn') ?? false;
print(status);
runApp(MaterialApp(home: status == true ? Login() : Home()));
}
更新:-
另一种实现方法是，您还可以将逻辑添加到启动屏幕中，并且启动屏幕应该是应用程序中的入口点
Another way of doing it is you can also add your logic into splash screen and splash screen should be entry point in your app
class SplashScreen extends StatefulWidget {
@override
State<StatefulWidget> createState() {
// TODO: implement createState
return _SplashScreenState();
}
}
class _SplashScreenState extends State<SplashScreen> {
@override
void initState() {
// TODO: implement initState
super.initState();
startTimer();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/clinician_splash.png"),
fit: BoxFit.cover),
),
),
);
}
void startTimer() {
Timer(Duration(seconds: 3), () {
navigateUser(); //It will redirect after 3 seconds
});
}
void navigateUser() async{
SharedPreferences prefs = await SharedPreferences.getInstance();
var status = prefs.getBool('isLoggedIn') ?? false;
print(status);
if (status) {
Navigation.pushReplacement(context, "/Home");
} else {
Navigation.pushReplacement(context, "/Login");
}
}
}
要注销，请在注销按钮的onPress事件中添加以下功能:
For logout add below functionality in onPress event of logout button :
void logoutUser(){
SharedPreferences prefs = await SharedPreferences.getInstance();
prefs?.clear()
Navigator.pushAndRemoveUntil(
context,
ModalRoute.withName("/SplashScreen"),
ModalRoute.withName("/Home")
);
}
这篇关于Flutter:如何保持用户登录和注销的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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