Flutter设备方向检测插件device_orientation_windows的使用

Flutter设备方向检测插件device_orientation_windows的使用

device_orientation_windows 是一个用于获取 Windows 设备方向的 Flutter 插件。它通过 wingdi 来实现这一功能。

获取开始

要获取当前设备的方向，可以使用以下代码：

DeviceOrientation deviceOrientation = await DeviceOrientationWindows.getDeviceOrientation();

要监听设备方向的变化事件，可以使用以下代码：

DeviceOrientation? deviceOrientation;
DeviceOrientationWindows.onOrientationChanged().listen((orientation) {
  deviceOrientation = orientation;
});

完整示例

下面是一个完整的示例代码，展示了如何在 Flutter 应用程序中使用 device_orientation_windows 插件来获取并监听设备方向的变化。

import 'dart:async';

import 'package:device_orientation_windows/device_orientation.dart';
import 'package:device_orientation_windows/device_orientation_windows.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart' as services;

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

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  DeviceOrientation _deviceOrientation = DeviceOrientation.unknown;
  StreamSubscription<DeviceOrientation>? _subscription;

  // 获取当前设备方向
  Future<void> getDeviceOrientation() async {
    DeviceOrientation deviceOrientation;
    try {
      deviceOrientation = await DeviceOrientationWindows.getDeviceOrientation();
    } on services.PlatformException {
      deviceOrientation = DeviceOrientation.unknown;
    }

    if (mounted) {
      setState(() {
        _deviceOrientation = deviceOrientation;
      });
    }
  }

  // 监听设备方向变化事件
  void listenOrientationChanged() {
    _subscription ??= 
        DeviceOrientationWindows.onOrientationChanged().listen((event) {
      if (mounted) {
        setState(() {
          _deviceOrientation = event;
        });
      }
    });
    setState(() {});
  }

  // 取消监听设备方向变化事件
  void cancelOrientationChanged() {
    _subscription?.cancel();
    setState(() {
      _subscription = null;
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('设备方向 Windows 示例'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Text('设备方向: ${_deviceOrientation.name}\n'),
              const SizedBox(height: 24),
              ElevatedButton(
                onPressed: getDeviceOrientation,
                child: const Text('获取设备方向'),
              ),
              const SizedBox(height: 24),
              ElevatedButton(
                onPressed: _subscription == null
                    ? listenOrientationChanged
                    : cancelOrientationChanged,
                child: _subscription == null
                    ? const Text('监听设备方向变化')
                    : const Text('取消监听设备方向变化'),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

说明

1. 获取当前设备方向：

   Future<void> getDeviceOrientation() async {
     DeviceOrientation deviceOrientation;
     try {
       deviceOrientation = await DeviceOrientationWindows.getDeviceOrientation();
     } on services.PlatformException {
       deviceOrientation = DeviceOrientation.unknown;
     }
   
     if (mounted) {
       setState(() {
         _deviceOrientation = deviceOrientation;
       });
     }
   }
   

   这段代码会尝试获取当前设备的方向，并将其存储在 _deviceOrientation 中。如果发生平台异常，则将方向设置为未知。

2. 监听设备方向变化：

   void listenOrientationChanged() {
     _subscription ??= 
         DeviceOrientationWindows.onOrientationChanged().listen((event) {
       if (mounted) {
         setState(() {
           _deviceOrientation = event;
         });
       }
     });
     setState(() {});
   }
   

   这段代码会创建一个流订阅来监听设备方向的变化。每当方向发生变化时，setState 会被调用来更新 UI。

3. 取消监听设备方向变化：

   void cancelOrientationChanged() {
     _subscription?.cancel();
     setState(() {
       _subscription = null;
     });
   }