flutter_orientation 是一个用于管理 Flutter 应用屏幕方向的插件。它允许你动态地控制应用的屏幕方向，例如锁定为竖屏、横屏，或者根据设备方向自动调整。

安装插件

首先，你需要在 pubspec.yaml 文件中添加 flutter_orientation 插件的依赖：

dependencies:
  flutter:
    sdk: flutter
  flutter_orientation: ^1.0.0

然后运行 flutter pub get 来安装插件。

使用插件

1. 导入插件

在你的 Dart 文件中导入 flutter_orientation 插件：

import 'package:flutter_orientation/flutter_orientation.dart';

2. 设置屏幕方向

你可以使用 FlutterOrientation.setOrientation 方法来设置屏幕方向。以下是一些常见的用法：

• 锁定为竖屏：

  FlutterOrientation.setOrientation(FlutterOrientation.PORTRAIT_UP);
  

• 锁定为横屏：

  FlutterOrientation.setOrientation(FlutterOrientation.LANDSCAPE_LEFT);
  

• 允许自动旋转：

  FlutterOrientation.setOrientation(FlutterOrientation.ALL);
  

3. 监听屏幕方向变化

你可以使用 FlutterOrientation.onOrientationChange 来监听屏幕方向的变化：

FlutterOrientation.onOrientationChange.listen((orientation) {
  print('Orientation changed to: $orientation');
});

4. 获取当前屏幕方向

你可以使用 FlutterOrientation.getOrientation 方法来获取当前的屏幕方向：

FlutterOrientation.getOrientation().then((orientation) {
  print('Current orientation: $orientation');
});

示例代码

以下是一个完整的示例，展示了如何使用 flutter_orientation 插件来管理屏幕方向：

import 'package:flutter/material.dart';
import 'package:flutter_orientation/flutter_orientation.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: OrientationScreen(),
    );
  }
}

class OrientationScreen extends StatefulWidget {
  [@override](/user/override)
  _OrientationScreenState createState() => _OrientationScreenState();
}

class _OrientationScreenState extends State<OrientationScreen> {
  String _currentOrientation = 'Unknown';

  [@override](/user/override)
  void initState() {
    super.initState();
    _getCurrentOrientation();
    FlutterOrientation.onOrientationChange.listen((orientation) {
      setState(() {
        _currentOrientation = orientation.toString();
      });
    });
  }

  void _getCurrentOrientation() async {
    var orientation = await FlutterOrientation.getOrientation();
    setState(() {
      _currentOrientation = orientation.toString();
    });
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Screen Orientation Example'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text('Current Orientation: $_currentOrientation'),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: () {
                FlutterOrientation.setOrientation(FlutterOrientation.PORTRAIT_UP);
              },
              child: Text('Lock Portrait'),
            ),
            ElevatedButton(
              onPressed: () {
                FlutterOrientation.setOrientation(FlutterOrientation.LANDSCAPE_LEFT);
              },
              child: Text('Lock Landscape'),
            ),
            ElevatedButton(
              onPressed: () {
                FlutterOrientation.setOrientation(FlutterOrientation.ALL);
              },
              child: Text('Allow Auto Rotation'),
            ),
          ],
        ),
      ),
    );
  }
}