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Flutter 如何在Flatter中使用SQFLite检查登录应用程序的用户凭据_Flutter_Dynamic_Future_Sqflite - Fatal编程技术网

Flutter 如何在Flatter中使用SQFLite检查登录应用程序的用户凭据

Flutter 如何在Flatter中使用SQFLite检查登录应用程序的用户凭据,flutter,dynamic,future,sqflite,Flutter,Dynamic,Future,Sqflite,在注册页面中,我尝试检查保存到表中的用户名和密码。如果表中存在用户名和密码,则处理用户导航并导航到其他屏幕用户 但当我尝试访问表并使用此方法检查用户名和密码时: Future<dynamic> checkLogin(String userName, String password) async { final dbClient = await db; return await dbClient.query(USER_TABLE, where: "$

在注册页面中,我尝试检查保存到表中的用户名和密码。如果表中存在用户名和密码,则处理用户导航并导航到其他屏幕用户

但当我尝试访问表并使用此方法检查用户名和密码时:

  Future<dynamic> checkLogin(String userName, String password) async {
    final dbClient = await db;
    return await dbClient.query(USER_TABLE,
        where: "$USERNAME = ?  AND $PASSWORD = ?",
        whereArgs: [userName, password],
        limit: 1);
  }
Future checkLogin(字符串用户名、字符串密码)异步{
最终数据库客户端=等待数据库;
return wait dbClient.query(用户表,
其中:“$USERNAME=?和$PASSWORD=?”,
wherergs:[用户名、密码],
限额:1),;
}
我得到了这个错误:
引发了另一个异常:“Future”类型不是“String”类型的子类型。

请指导我如何更改此方法以获取用户名和密码,然后根据结果处理用户导航? 谢谢你的帮助

编辑:

登录\u screen.dart:

import 'package:atlas_gen_demo/screens/register_screen.dart';
import 'package:flutter/material.dart';
import 'package:atlas_gen_demo/Animation/FadeAnimation.dart';
import 'package:flushbar/flushbar.dart';
import 'package:atlas_gen_demo/data/storage/db_helper.dart';

class LoginScreen extends StatelessWidget {
  static const routeName = '/login';

  var dbHelper;

  final usernameController = TextEditingController();
  final passwordController = TextEditingController();

  void navigateToRegister(BuildContext ctx) {
    Navigator.of(ctx).pushNamed(
      RegisterScreen.routeName,
    );
  }

  validate(BuildContext ctx) {
    if (usernameController.text != "" && passwordController.text != "") {
      dbHelper = DBHelper();

      var test =
          dbHelper.checkLogin(usernameController.text, passwordController.text);
      // just for test what we got here
      showFlushBar(ctx, "test", test);
      //navigateToUsersList(ctx);
    } else {
      showFlushBar(ctx, "خطا", "اطلاعات را وارد نمایید");
    }
  }

  void navigateToUsersList(BuildContext ctx) {
    Navigator.of(ctx).pushNamed(
      LoginScreen.routeName,
    );
  }

  void showFlushBar(BuildContext context, String title, String text) {
    Flushbar(
      padding: EdgeInsets.all(10),
      borderRadius: 8,
      backgroundGradient: LinearGradient(
        colors: [Colors.purple.shade800, Colors.purpleAccent.shade700],
        stops: [0.6, 1],
      ),
      boxShadows: [
        BoxShadow(
          color: Colors.black,
          offset: Offset(3, 3),
          blurRadius: 3,
        )
      ],
      dismissDirection: FlushbarDismissDirection.HORIZONTAL,
      forwardAnimationCurve: Curves.fastLinearToSlowEaseIn,
      titleText: Text(
        title,
        style: TextStyle(fontFamily: 'mainBold', color: Colors.white),
      ),
      messageText: Text(
        text,
        style: TextStyle(fontFamily: 'mainMedium', color: Colors.white),
      ),
      duration: Duration(seconds: 3),
    ).show(context);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      body: SingleChildScrollView(
        child: Container(
          child: Column(
            children: <Widget>[
              Container(
                height: 250,
                margin: EdgeInsets.only(top: 50),
                decoration: BoxDecoration(
                  image: DecorationImage(
                    image: AssetImage('assets/images/login.png'),
                    fit: BoxFit.fill,
                  ),
                ),
              ),
              Positioned(
                child: FadeAnimation(
                    1.8,
                    Container(
                      margin: EdgeInsets.only(top: 10),
                      child: Center(
                        child: Text(
                          "ورود به برنامه",
                          textAlign: TextAlign.center,
                          style: TextStyle(
                            color: Color.fromRGBO(143, 148, 251, 1),
                            fontSize: 30,
                            fontWeight: FontWeight.bold,
                            fontFamily: 'persianBold',
                          ),
                        ),
                      ),
                    )),
              ),
              Padding(
                padding: EdgeInsets.all(30.0),
                child: Column(
                  children: <Widget>[
                    Container(
                      padding: EdgeInsets.all(5),
                      decoration: BoxDecoration(
                        color: Colors.white,
                        borderRadius: BorderRadius.circular(10),
                        boxShadow: [
                          BoxShadow(
                              color: Color.fromRGBO(143, 148, 251, .2),
                              blurRadius: 20.0,
                              offset: Offset(0, 10))
                        ],
                      ),
                      child: Column(
                        children: <Widget>[
                          Container(
                            padding: EdgeInsets.all(8.0),
                            decoration: BoxDecoration(
                                border: Border(
                              bottom: BorderSide(color: Colors.grey[100]),
                            )),
                            child: TextFormField(
                              controller: usernameController,
                              textDirection: TextDirection.rtl,
                              textAlign: TextAlign.right,
                              decoration: InputDecoration(
                                border: InputBorder.none,
                                hintText: "نام کاربری",
                                hintStyle: TextStyle(
                                  color: Colors.grey[400],
                                  fontFamily: 'persianMedium',
                                  fontSize: 14,
                                ),
                              ),
                            ),
                          ),
                          Container(
                            padding: EdgeInsets.all(8.0),
                            child: TextFormField(
                              controller: passwordController,
                              textAlign: TextAlign.right,
                              textDirection: TextDirection.rtl,
                              decoration: InputDecoration(
                                border: InputBorder.none,
                                hintText: "کلمه عبور",
                                hintStyle: TextStyle(
                                  color: Colors.grey[400],
                                  fontFamily: 'persianMedium',
                                  fontSize: 14,
                                ),
                              ),
                            ),
                          ),
                        ],
                      ),
                    ),
                    SizedBox(
                      height: 30,
                    ),
                    FadeAnimation(
                        2,
                        InkWell(
                          onTap: () => validate(context),
                          child: Container(
                            height: 50,
                            decoration: BoxDecoration(
                              borderRadius: BorderRadius.circular(10),
                              gradient: LinearGradient(
                                colors: [
                                  Color.fromRGBO(143, 148, 251, .4),
                                  Color.fromRGBO(143, 148, 251, .8),
                                ],
                              ),
                            ),
                            child: Center(
                              child: Text(
                                "ورود به برنامه",
                                style: TextStyle(
                                  color: Colors.white,
                                  fontWeight: FontWeight.bold,
                                  fontFamily: 'persianBold',
                                  fontSize: 18,
                                ),
                              ),
                            ),
                          ),
                        )),
                    SizedBox(
                      height: 40,
                    ),
                    FadeAnimation(
                        1.5,
                        InkWell(
                          onTap: () => navigateToRegister(context),
                          child: Text(
                            "ثبت نام در برنامه",
                            style: TextStyle(
                              fontFamily: 'persianMedium',
                              fontSize: 14,
                              color: Color.fromRGBO(143, 148, 251, .6),
                            ),
                          ),
                        )),
                  ],
                ),
              )
            ],
          ),
        ),
      ),
    );
  }
}
import'包:atlas_gen_demo/screens/register_screen.dart';
进口“包装:颤振/材料.省道”;
导入“包:atlas_gen_demo/Animation/FadeAnimation.dart”;
导入“包:flushbar/flushbar.dart”;
导入“包:atlas_gen_demo/data/storage/db_helper.dart”;
类LoginScreen扩展了无状态小部件{
静态常量routeName='/login';
var-dbHelper;
最终用户名控制器=TextEditingController();
最终密码控制器=TextEditingController();
无效导航寄存器(BuildContext ctx){
Navigator.of(ctx.pushName)(
RegisterScreen.routeName,
);
}
验证(BuildContext ctx){
if(usernameController.text!=“”&passwordController.text!=“”){
dbHelper=dbHelper();
var检验=
dbHelper.checkLogin(usernameController.text、passwordController.text);
//只是为了测试我们在这里得到了什么
显示冲洗条(ctx,“测试”,测试);
//导航用户列表(ctx);
}否则{
showFlushBar(ctx、ctx、ctx、ctx);
}
}
无效navigateToUsersList(BuildContext ctx){
Navigator.of(ctx.pushName)(
LoginScreen.routeName,
);
}
void showFlushBar(构建上下文上下文、字符串标题、字符串文本){
冲水杆(
填充:边缘设置。全部(10),
边界半径:8,
背景梯度:线性梯度(
颜色:[colors.purple.shade800,colors.purpleacent.shade700],
停止:[0.6,1],
),
箱形阴影:[
箱形阴影(
颜色:颜色,黑色,
偏移量:偏移量(3,3),
半径:3,
)
],
dismissDirection:FlushbarDismissDirection.HORIZONTAL,
forwardAnimationCurve:Curves.FastLinearToSloweasin,
标题文本:文本(
标题
样式:TextStyle(fontFamily:'mainBold',颜色:Colors.white),
),
messageText:Text(
文本,
样式:TextStyle(fontFamily:'mainMedium',颜色:Colors.white),
),
持续时间:持续时间(秒数:3),
).show(上下文);
}
@凌驾
小部件构建(构建上下文){
返回脚手架(
背景颜色:Colors.white,
正文:SingleChildScrollView(
子:容器(
子:列(
儿童:[
容器(
身高:250,
页边距:仅限边缘集(顶部:50),
装饰:盒子装饰(
图像:装饰图像(
image:AssetImage('assets/images/login.png'),
fit:BoxFit.fill,
),
),
),
定位(
孩子:FadeAnimation(
1.8,
容器(
页边空白:仅限边集(前10页),
儿童:中心(
子:文本(
"ورود به برنامه",
textAlign:textAlign.center,
样式:TextStyle(
颜色:颜色。来自RGBO(143148251,1),
尺寸:30,
fontWeight:fontWeight.bold,
fontFamily:“波斯博尔德”,
),
),
),
)),
),
填充物(
填充:所有边缘设置(30.0),
子:列(
儿童:[
容器(
填充:边缘设置。全部(5),
装饰:盒子装饰(
颜色:颜色,白色,
边界半径:边界半径。圆形(10),
boxShadow:[
箱形阴影(
颜色:颜色。来自RGBO(143148251,.2),
半径:20.0,
偏移量:偏移量(0,10))
],
),
子:列(
儿童:[
容器(
填充:边缘设置。全部(8.0),
装饰:盒子装饰(
边界:边界(
底部:边框边(颜色:Colors.grey[100]),
)),
子项:TextFormField(
控制器:usernameController,
textDirection:textDirection.rtl,
textAlign:textAlign.right,
装饰:输入装饰(
边框:InputBorder.none,
hintText:“نامکابی”,
hintStyle:TextStyle(
颜色:颜色。灰色[400],
fontFamily:“波斯媒体”,
import 'dart:async';
import 'dart:io' as io;
import 'package:path/path.dart';
import 'package:sqflite/sqflite.dart';
import 'package:path_provider/path_provider.dart';
import '../../models/user.dart';

class DBHelper {
  static Database _db;
  static const String ID = 'id';
  static const String NAME = 'name';
  static const String FAMILY = 'family';
  static const String USERNAME = 'username';
  static const String PASSWORD = 'password';
  static const String BIRTHDAY = 'birthday';
  static const String MOBILE = 'mobile';
  static const String NATIONAL_ID = 'nationalId';
  static const String USER_TABLE = 'User';
  static const String DB_NAME = 'user.db';

  Future<Database> get db async {
    if (_db != null) {
      return _db;
    }

    _db = await initDb();

    return _db;
  }

  initDb() async {
    io.Directory documentDirectory = await getApplicationDocumentsDirectory();
    String path = join(documentDirectory.path, DB_NAME);
    var db = await openDatabase(path, version: 1, onCreate: _onCreate);
    return db;
  }

  _onCreate(Database db, int version) async {
    await db.execute(
        "CREATE TABLE $USER_TABLE ($ID INTEGER PRIMARY KEY, $NAME TEXT, $FAMILY TEXT, $USERNAME TEXT NOT NULL, $PASSWORD TEXT , $BIRTHDAY TEXT, $MOBILE TEXT, $NATIONAL_ID TEXT UNIQUE)");
  }

  Future<User> save(User user) async {
    var dbClient = await db;
    user.id = await dbClient.insert(USER_TABLE, user.toMap());
    return user;
  }

  Future<List<User>> getUsers() async {
    var dbClient = await db;
    List<Map> maps = await dbClient.query(USER_TABLE, columns: [
      ID,
      NAME,
      FAMILY,
      USERNAME,
      PASSWORD,
      BIRTHDAY,
      MOBILE,
      NATIONAL_ID
    ]);

    List<User> users = [];

    if (maps.length > 0) {
      for (int i = 0; i < maps.length; i++) {
        users.add(User.fromMap(maps[i]));
      }
    }
    return users;
  }

  Future<dynamic> getUser(String nationalId) async {
    final dbClient = await db;
    return await dbClient.query(USER_TABLE,
        where: "$NATIONAL_ID = ?", whereArgs: [nationalId], limit: 1);
  }

  Future<User> checkLogin(String userName, String password) async {
    final dbClient = await db;
    var res = await dbClient.rawQuery(
        "SELECT * FROM $USER_TABLE WHERE username = '$userName' and password = '$password'");

    if (res.length > 0) {
      return new User.fromMap(res.first);
    }

    return null;
  }

  Future<int> delete(String nationalId) async {
    var dbClient = await db;
    return await dbClient
        .delete(USER_TABLE, where: '$nationalId = ?', whereArgs: [nationalId]);
  }

  Future<int> update(User user) async {
    var dbClient = await db;
    return await dbClient.update(USER_TABLE, user.toMap(),
        where: '$NATIONAL_ID = ?', whereArgs: [user.nationalId]);
  }

  Future close() async {
    var dbClient = await db;
    dbClient.close();
  }
}
   validate(BuildContext ctx) async {
        if (usernameController.text != "" && passwordController.text != "") {
          dbHelper = DBHelper();

          User test =
              await dbHelper.checkLogin(usernameController.text, passwordController.text);
          // just for test what we got here
          showFlushBar(ctx, "test", test.toString());
          //navigateToUsersList(ctx);
        } else {
          showFlushBar(ctx, "خطا", "اطلاعات را وارد نمایید");
        }
      }