flutter - 如何在 Flutter 的页面认证中保存用户登录？

问题描述

我有一个授权页面，一切正常，我在服务器上登录，没有任何问题。但是我有一个问题，我不能这样做，当我登录以在下一次授权时将我的登录信息保存在系统中时（即通过单击登录字段，我必须看到至少最后 3 个已被授权的唯一登录信息，然后我只选择了我需要的登录名并输入我的密码）我的页面验证码：
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'dart:io';
import  'package:flutter_app_seals/model/setting/globalvar.dart' as global;
import 'package:flutter_aes_ecb_pkcs5/flutter_aes_ecb_pkcs5.dart';
import 'package:flutter/widgets.dart';
import 'package:path_provider/path_provider.dart';
import 'package:flutter/foundation.dart';
import  'package:flutter_app_seals/model/user_page/page.dart' ;



class Login extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
        home: new LoginPage(
            storage: Storage()
        )
    );
  }
}

class LoginPage extends StatefulWidget {

  final Storage storage;

  LoginPage({Key key, @required this.storage}) : super(key: key);

  @override
  _LoginPageState createState() => _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {
  //Info about users
  String state;

  @override
  void initState() {
    super.initState();
    widget.storage.readData().then((String value) {
      setState(() {
        global.urlVar = value;
      });
    });
  }

  bool _isLoading = false;

  @override
  Widget build(BuildContext context) {
    SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle.light.copyWith(statusBarColor: Colors.transparent));
    return Scaffold(
      body: Container(
        decoration: BoxDecoration(
          gradient: LinearGradient(
              colors: [Colors.blue, Colors.white],
              begin: Alignment.topCenter,
              end: Alignment.bottomCenter),
        ),
        child: _isLoading ? Center(child: CircularProgressIndicator()) : ListView(
          children: <Widget>[
            headerSection(),
            textSection(),
            buttonSection(),

          ],
        ),
      ),
    );
  }


  signIn(String login, pass) async {
    SharedPreferences sharedPreferences = await SharedPreferences.getInstance();

    var AESLogin = login;
    var AESpass = pass;
    //generate a 16-byte random key
    var key = '1212121211121112';

    print(key);
    //encrypt
    var encryptLogin = await FlutterAesEcbPkcs5.encryptString(AESLogin, key);
    var encryptPass = await FlutterAesEcbPkcs5.encryptString(AESpass, key);




    HttpClient client = new HttpClient();
    client.badCertificateCallback = ((X509Certificate cert, String host, int port) => true);


    String url = global.urlVar + "/auth";

    Map map = {
      "login": encryptLogin,
      "pass": encryptPass
    };

    HttpClientRequest request = await client.postUrl(Uri.parse(url));

    request.headers.set('content-type', 'application/json');

    request.add(utf8.encode(json.encode(map)));

    HttpClientResponse response = await request.close();


    var responseBody = await response.transform(utf8.decoder).join();

    Map jsonResponse = json.decode(responseBody);

    print(jsonResponse);

    if (response.statusCode == 200) {
      if (jsonResponse['message'] ==
          '200') { //if( jsonResponse['message'] == '200') {
        setState(() {

          _isLoading = false;
        });

        global.nameUser = jsonResponse['name'];
        global.dataArea = jsonResponse['data_area'];

        Navigator.pushReplacement(
          context,
          MaterialPageRoute(builder: (context) => UserPage()),
        ).then((value) {
          setState(( ) {});
        });
      }
      else {
        Navigator.push(
          context,
          MaterialPageRoute(builder: (context) => Error_Auth()),
        );
      }
    }

    else   {
      setState(() {
        _isLoading = false;
      });
    }
  }

  Container buttonSection() {
    return Container(
      width: MediaQuery.of(context).size.width,
      height: 40.0,
      padding: EdgeInsets.symmetric(horizontal: 15.0),
      margin: EdgeInsets.only(top: 15.0),
      child: RaisedButton(
        onPressed: emailController.text == "" || passwordController.text == "" ? null : () {
          setState(() {
            _isLoading = true;
          });
          signIn(emailController.text, passwordController.text);
        },
        elevation: 0.0,
        color: Colors.purple,
        child: Text("SingIn", style: TextStyle(color: Colors.white70)),
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(5.0)),
      ),
    );
  }

  final TextEditingController emailController = new TextEditingController();
  final TextEditingController passwordController = new TextEditingController();

  Container textSection() {
    return Container(
      padding: EdgeInsets.symmetric(horizontal: 15.0, vertical: 20.0),
      child: Column(
        children: <Widget>[
          TextFormField(
            controller: emailController,
            cursorColor: Colors.white,

            style: TextStyle(color: Colors.white70),
            decoration: InputDecoration(
              icon: Icon(Icons.login, color: Colors.white70),
              hintText: "Login",
              border: UnderlineInputBorder(borderSide: BorderSide(color: Colors.white70)),
              hintStyle: TextStyle(color: Colors.white70),
            ),
          ),
          SizedBox(height: 30.0),
          TextFormField(
            controller: passwordController,
            cursorColor: Colors.white,
            obscureText: true,
            style: TextStyle(color: Colors.white70),
            decoration: InputDecoration(
              icon: Icon(Icons.lock, color: Colors.white70),
              hintText: "Pass",
              border: UnderlineInputBorder(borderSide: BorderSide(color: Colors.white70)),
              hintStyle: TextStyle(color: Colors.white70),
            ),
          ),

        ],
      ),

    );
  }

  Container headerSection() {
    return Container(
      alignment: Alignment.topCenter,
      margin: EdgeInsets.only(top: 50.0),
      child: Text("Пломби",
          style: TextStyle(
              color: Colors.white70,
              fontSize: 40.0,
              fontWeight: FontWeight.bold)),
    );
  }
}
class Error_Auth extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final AlertDialog dialog = AlertDialog(
      title: Text('Помилка при авторизації'),
      content:
      Text('Повторити спробу авторизації'),
      actions: [
        FlatButton(
          textColor: Color(0xFF6200EE),
          onPressed: () => SystemNavigator.pop(),
          child: Text('Ні'),
        ),
        FlatButton(
          textColor: Color(0xFF6200EE),
          onPressed: () {  Navigator.push(
            context,MaterialPageRoute(builder: (context) => Login()),
          );
          },
          child: Text('Так'),
        ),
      ],
    );
    return Scaffold(
        body:dialog
    );
  }
}

class Storage {
  Future<String> get localPath async {
    final dir = await getApplicationDocumentsDirectory();
    return dir.path;
  }

  Future<File> get localFile async {
    final path = await localPath;
    return File('$path/db.txt');
  }

  Future<String> readData() async {
    try {
      final file = await localFile;
      String body = await file.readAsString();

      return body;
    } catch (e) {
      return e.toString();
    }
  }

  Future<File> writeData(String data) async {
    final file = await localFile;
    return file.writeAsString("$data");
  }
}
我的纱布：
标签： flutterdart
flutter - 如何在 Flutter 的页面认证中保存用户登录？

问题描述

解决方案

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