Android 12模拟器中Flutter camera插件takePicture方法无响应

环境信息 #

• camera插件版本：0.10.5+2
• 测试环境：Android 12 Pixel 6模拟器

问题现象 #

调用CameraController.takePicture()方法时，程序出现卡死或进入无限循环，后续代码无法执行，且无任何异常抛出。例如以下两个示例中，print('A picture was captured.')语句始终不会执行：

无状态组件示例 #

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

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  final cameraController = CameraController(
    (await availableCameras())[0],
    ResolutionPreset.max,
  );

  await cameraController.initialize();

  final app = MaterialApp(
    home: CameraScreen(
      controller: cameraController,
    ),
  );

  runApp(app);
}

class CameraScreen extends StatelessWidget {
  const CameraScreen({
    super.key,
    required this.controller,
  });

  final CameraController controller;

  Future<void> takePicture() async {
    await controller.takePicture(); // 此调用永远不会返回
    print('A picture was captured.'); // 该行代码永远不会执行
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Column(
          children: [
            CameraPreview(controller),
            ElevatedButton(
              onPressed: takePicture,
              child: const Text('TAKE PICTURE'),
            )
          ],
        ),
      ),
    );
  }
}

有状态组件示例 #

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

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  final app = MaterialApp(
    home: CameraScreen(
      description: (await availableCameras())[0],
    ),
  );

  runApp(app);
}

class CameraScreen extends StatefulWidget {
  const CameraScreen({
    super.key,
    required this.description,
  });

  final CameraDescription description;

  @override
  State<CameraScreen> createState() => _CameraScreenState();
}

class _CameraScreenState extends State<CameraScreen> {
  late CameraController controller;

  Future<void> takePicture() async {
    await controller.takePicture(); // 此调用永远不会返回
    print('A picture was captured.'); // 该行代码永远不会执行
  }

  @override
  void initState() {
    controller = CameraController(
      widget.description,
      ResolutionPreset.max,
    );

    if (controller.value.isInitialized == false) {
      controller.initialize();
    }

    super.initState();
  }

  @override
  void dispose() {
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Column(
          children: [
            CameraPreview(controller),
            ElevatedButton(
              onPressed: takePicture,
              child: const Text('TAKE PICTURE'),
            )
          ],
        ),
      ),
    );
  }
}

解决方案 #

1. 确保相机完全初始化后再操作 #

有状态组件示例中，initState里的相机初始化未使用await，也未监听初始化状态，可能导致拍照时相机未就绪引发阻塞。修改初始化逻辑：

@override
void initState() {
  super.initState();
  controller = CameraController(
    widget.description,
    ResolutionPreset.max,
  );
  _initCamera();
}

Future<void> _initCamera() async {
  try {
    await controller.initialize();
    if (mounted) setState(() {});
  } catch (e) {
    print('相机初始化失败: $e');
  }
}

2. 给拍照方法添加状态检查与异常捕获 #

增加相机状态校验，防止重复调用，并捕获可能的异常：

Future<void> takePicture() async {
  if (!controller.value.isInitialized) {
    print('相机未初始化');
    return;
  }
  if (controller.value.isTakingPicture) {
    return; // 避免重复触发拍照
  }
  try {
    final XFile picture = await controller.takePicture();
    print('照片已保存至: ${picture.path}');
  } catch (e) {
    print('拍照失败: $e');
  }
}

3. 升级camera插件版本 #

0.10.5+2版本存在Android 12兼容性问题，建议升级至最新稳定版（如0.13.x及以上），新版本修复了多个平台适配bug。

4. 调整模拟器配置 #

• 在AVD管理器中，确保目标设备的相机功能已启用（进入设备的“Show Advanced Settings”，将Camera选项设置为“Emulated”或关联真实相机）
• 尝试降低分辨率预设，例如使用ResolutionPreset.medium代替max，高分辨率在模拟器上易引发性能瓶颈

内容的提问来源于stack exchange，提问作者XUNIT