topicApp/lib/main.dart

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:topic/HomePage.dart';
import 'package:mysql_client/mysql_client.dart';
import 'package:topic/NoSwipeBackRoute.dart';
import 'package:topic/RegisterPage.dart';

void main() {
  runApp(MaterialApp(
    home: LoginPage(),
  ));
}

class LoginPage extends StatefulWidget {
  @override
  _LoginPageState createState() => _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {
  final TextEditingController _emailController = TextEditingController();
  final TextEditingController _ageController = TextEditingController();
  bool _passwordNotVisible = true;

  @override
  void initState() {
    //初始化
    super.initState();
    _fetchData(); //連資料庫
    _CheckPreLoginInfo(); //確定有先前有無登入
  }

  void _fetchData() async {
    //MYSQL
    final conn = await MySQLConnection.createConnection(
      host: '203.64.84.154',
      // host:'10.0.2.2',
      //127.0.0.1 10.0.2.2
      port: 33061,
      userName: 'root',
      password: 'Topic@2024',
      // password: '0000',
      databaseName: 'care', //testdb
      // databaseName: 'testdb',
    );
    await conn.connect();
  }

  void _CheckPreLoginInfo() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    //get user data from share preference else set empty to check not login before
    String loginUserEmail = prefs.getString("email") ?? "";
    //replace screen to HomePage if there are previous data in share preference
    if (loginUserEmail != "") {
      Navigator.pushReplacement(
        context,
        NoSwipeBackRoute(
          builder: (context) => HomePage(
            email: loginUserEmail,
          ),
        ),
      );
    }
  }

  void _setLoginInfo(String email) async {
    //save user email into share preference to let app can auto login next open
    SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.setString("email", email);
  }

  void loginBtn() async {
    final conn = await MySQLConnection.createConnection(
      host: '203.64.84.154',
      // host:'10.0.2.2',
      //127.0.0.1 10.0.2.2
      port: 33061,
      userName: 'root',
      password: 'Topic@2024',
      // password: '0000',
      databaseName: 'care', //testdb
      // databaseName: 'testdb',
    );
    await conn.connect();

    try {
      // 獲取用戶輸入的帳號和密碼
      String email = _emailController.text;
      String password = _ageController.text;

      print('输入的信箱: $email');
      print('输入的密碼: $password');

      // 查詢數據庫，检查是否有匹配的帳號
      var result = await conn.execute(
        'SELECT * FROM HomeLogin WHERE homeEmail = :email AND homePassword = :password',
        {'email': email, 'password': password},
      );

      print('查詢結果行數: ${result.rows.length}');

      if (result.rows.isNotEmpty) {
        _emailController.clear();
        _ageController.clear();
        // 如果找到匹配的帳號，登入成功，跳轉到主頁
        _setLoginInfo(email);
        Navigator.pushReplacement(
          context,
          NoSwipeBackRoute(
            builder: (context) => HomePage(
              email: email,
            ),
          ),
        );
      } else {
        // 没有找到匹配的帳號，提示登入失敗
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('登入失敗：帳號或密碼錯誤')),
        );
      }
    } catch (e) {
      print('資料庫錯誤: $e');
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('登入失敗：系統錯誤')),
      );
    } finally {
      await conn.close();
    }
  }

  @override
  Widget build(BuildContext context) {
    debugPaintSizeEnabled = false;
    //by use PopScope and disable can Pop avoid android user pop back by back button
    return PopScope(
      canPop: false,
      child: Scaffold(
        body: SafeArea(
          child: Center(
            child: SingleChildScrollView(
              child: Padding(
                padding: const EdgeInsets.symmetric(horizontal: 32.0),
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    Container(
                      margin: EdgeInsets.only(bottom: 40), // 添加間距
                      height: 100, // 設置logo高度
                      child: Icon(
                        Icons.account_circle,
                        size: 100, // 設置圖標大小
                        color: Color(0xFF4FC3F7), // 設置圖標颜色
                      ),
                    ),
                    Text(
                      '全方位照護守護者',
                      style: TextStyle(
                        fontSize: 32,
                        fontWeight: FontWeight.bold,
                        color: Colors.black,
                      ),
                    ), //全方位照護守護者
                    SizedBox(height: 20),
                    TextField(
                      controller: _emailController, // 绑定電子信箱输入框的控制器
                      decoration: InputDecoration(
                        border: OutlineInputBorder(),
                        prefixIcon: Icon(Icons.email_outlined),
                        //https://www.fluttericon.cn/v
                        labelText: '電子信箱',
                      ),
                    ), //電子信箱
                    SizedBox(height: 20),
                    TextField(
                      controller: _ageController,
                      decoration: InputDecoration(
                        border: OutlineInputBorder(),
                        prefixIcon: Icon(Icons.lock_outlined),
                        suffixIcon: IconButton(
                          icon: Icon(_passwordNotVisible
                              ? Icons.visibility
                              : Icons.visibility_off),
                          onPressed: () {
                            setState(
                              () {
                                _passwordNotVisible = !_passwordNotVisible;
                              },
                            );
                          },
                        ),
                        labelText: '密碼',
                      ),
                      obscureText: _passwordNotVisible,
                    ), //密碼
                    SizedBox(height: 20),
                    ElevatedButton(
                      onPressed: loginBtn,
                      /*() {
                        Navigator.push(
                          context,
                          MaterialPageRoute(builder: (context) => HomePage()),
                        );
                      },*/
                      child: Text(' 登入'),
                      style: ElevatedButton.styleFrom(
                        backgroundColor: Color(0xFF4FC3F7),
                        padding:
                            EdgeInsets.symmetric(horizontal: 50, vertical: 15),
                        textStyle: TextStyle(fontSize: 18),
                      ),
                    ), //登入
                    SizedBox(height: 10),
                    ElevatedButton(
                      onPressed: () {
                        Navigator.push(
                          context,
                          MaterialPageRoute(
                              builder: (context) => RegisterPage()),
                        );
                      },
                      child: Text('立即註冊'),
                      style: TextButton.styleFrom(
                        backgroundColor: Colors.transparent, // 無背景颜色
                        textStyle: TextStyle(fontSize: 18),
                        shadowColor: Colors.transparent, // 去除陰影
                      ),
                    ),
                    ElevatedButton(
                      onPressed: () {
                        Navigator.push(
                          context,
                          MaterialPageRoute(
                              builder: (context) => HomePage(
                                    email: _emailController.text,
                                  )),
                        );
                      },
                      child: Text('忘記密碼'),
                      style: TextButton.styleFrom(
                        backgroundColor: Colors.transparent, // 無背景颜色
                        textStyle: TextStyle(fontSize: 18),
                        shadowColor: Colors.transparent, // 去除陰影
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}