import 'package:flutter/material.dart';

class MyTextWidget extends StatelessWidget {
  final String text;

  const MyTextWidget({super.key, required this.text});

  @override
  Widget build(BuildContext context) {
    return Text(
      text,
      style: const TextStyle(
        fontSize: 18,
        color: Colors.blue,
      ),
    );
  }
}

// 使用
class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: MyTextWidget(text: 'Hello, Widget!'),
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';

class CounterWidget extends StatefulWidget {
  const CounterWidget({super.key});

  @override
  State createState() => _CounterWidgetState();
}

class _CounterWidgetState extends State {
  int _count = 0;

  void _increment() {
    setState(() {
      _count++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        Text(
          '计数: $_count',
          style: const TextStyle(fontSize: 24),
        ),
        const SizedBox(height: 20),
        ElevatedButton(
          onPressed: _increment,
          child: const Text('增加'),
        ),
      ],
    );
  }
}

Container(
  width: 200,
  height: 200,
  padding: const EdgeInsets.all(20),
  margin: const EdgeInsets.symmetric(horizontal: 10),
  decoration: BoxDecoration(
    color: Colors.blue,
    borderRadius: BorderRadius.circular(10),
    boxShadow: [
      BoxShadow(
        color: Colors.black.withOpacity(0.2),
        blurRadius: 10,
        spreadRadius: 5,
      ),
    ],
  ),
  child: const Center(
    child: Text(
      'Container',
      style: TextStyle(color: Colors.white, fontSize: 18),
    ),
  ),
)

const Text(
  'Hello, Flutter!',
  style: TextStyle(
    fontSize: 24,
    fontWeight: FontWeight.bold,
    color: Colors.blue,
    letterSpacing: 1.5,
    wordSpacing: 2.0,
  ),
  textAlign: TextAlign.center,
)

// 从网络加载图片
Image.network(
  'https://example.com/image.jpg',
  width: 200,
  height: 200,
  fit: BoxFit.cover,
)

// 从资源加载图片
Image.asset('assets/images/logo.png')

// 从文件加载
Image.file(File('/path/to/image.jpg'))

const Icon(
  Icons.favorite,
  size: 48,
  color: Colors.red,
)

// 自定义颜色和大小
Icon(
  Icons.star,
  color: Colors.yellow,
  size: 32,
)

// ElevatedButton（Material 风格凸起按钮）
ElevatedButton(
  onPressed: () {
    print('ElevatedButton 被点击');
  },
  style: ElevatedButton.styleFrom(
    backgroundColor: Colors.blue,
    padding: const EdgeInsets.symmetric(
      horizontal: 20,
      vertical: 15,
    ),
  ),
  child: const Text('点击我'),
)

// TextButton（文本按钮）
TextButton(
  onPressed: () {},
  child: const Text('文本按钮'),
)

// OutlinedButton（轮廓按钮）
OutlinedButton(
  onPressed: () {},
  style: OutlinedButton.styleFrom(
    side: const BorderSide(color: Colors.blue),
  ),
  child: const Text('轮廓按钮'),
)

// IconButton（图标按钮）
IconButton(
  onPressed: () {},
  icon: const Icon(Icons.favorite),
  iconSize: 32,
  color: Colors.red,
)

TextField(
  decoration: InputDecoration(
    labelText: '用户名',
    hintText: '请输入用户名',
    prefixIcon: const Icon(Icons.person),
    border: OutlineInputBorder(
      borderRadius: BorderRadius.circular(10),
    ),
    filled: true,
    fillColor: Colors.grey[100],
  ),
  onChanged: (value) {
    print('输入: $value');
  },
  onSubmitted: (value) {
    print('提交: $value');
  },
)

class LifecycleWidget extends StatefulWidget {
  const LifecycleWidget({super.key});

  @override
  State createState() => _LifecycleWidgetState();
}

class _LifecycleWidgetState extends State {
  @override
  void initState() {
    super.initState();
    print('initState: Widget 初始化');
    // 初始化操作，如加载数据
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    print('didChangeDependencies: 依赖变化');
    // 依赖项（如 Theme）变化时调用
  }

  @override
  void didUpdateWidget(LifecycleWidget oldWidget) {
    super.didUpdateWidget(oldWidget);
    print('didUpdateWidget: Widget 更新');
    // 父 Widget 重建时调用
  }

  @override
  void setState(VoidCallback fn) {
    super.setState(fn);
    print('setState: 状态更新');
  }

  @override
  void deactivate() {
    super.deactivate();
    print('deactivate: Widget 即将被移除');
  }

  @override
  void dispose() {
    super.dispose();
    print('dispose: Widget 被销毁');
    // 清理资源，如关闭流、取消订阅
  }

  @override
  Widget build(BuildContext context) {
    print('build: Widget 构建');
    return Container(
      child: const Text('生命周期示例'),
    );
  }
}