从无到有，Flutter手势密码插件全开发流程

2024-01-28 13:20:55

Flutter 手势密码插件开发指南

开发

创建新项目

首先，使用 Flutter CLI 创建一个新的 Flutter 项目：

flutter create hand_gesture_password

添加依赖项

在项目的 pubspec.yaml 文件中添加以下依赖项：

dependencies:
  flutter:
    sdk: flutter
  provider: ^6.0.3

开发手势密码功能

实现手势监听器

创建 HandGestureListener 小部件，用于监听手势并记录密码：

class HandGestureListener extends StatefulWidget {
  final ValueChanged<List<Offset>> onGesture;

  const HandGestureListener({Key? key, required this.onGesture}) : super(key: key);

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

class _HandGestureListenerState extends State<HandGestureListener> {
  List<Offset> points = [];

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onPanUpdate: (details) {
        setState(() {
          points.add(details.localPosition);
        });
      },
      onPanEnd: (details) {
        widget.onGesture(points);
        points.clear();
      },
      child: Container(),
    );
  }
}

实现密码验证器

创建 PasswordVerifier 类，用于验证输入的手势密码是否正确：

class PasswordVerifier {
  final List<Offset> correctPassword;

  const PasswordVerifier({required this.correctPassword});

  bool verify(List<Offset> input) {
    return listEquals(correctPassword, input);
  }
}

组合小部件

将 HandGestureListener 和 PasswordVerifier 小部件组合到 HandGesturePassword 小部件中，用于显示手势密码界面并处理输入：

class HandGesturePassword extends StatefulWidget {
  final List<Offset> correctPassword;

  const HandGesturePassword({Key? key, required this.correctPassword}) : super(key: key);

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

class _HandGesturePasswordState extends State<HandGesturePassword> {
  late PasswordVerifier verifier;

  @override
  void initState() {
    super.initState();
    verifier = PasswordVerifier(correctPassword: widget.correctPassword);
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        HandGestureListener(
          onGesture: (points) {
            if (verifier.verify(points)) {
              // 验证成功
            } else {
              // 验证失败
            }
          },
        ),
      ],
    );
  }
}