Flutter - 原生交互 - 相机Camera - 02

环境

Flutter 3.29

macOS Sequoia 15.4.1

Xcode 16.3

集成

1. 创建一个带有 State 类的 StatefulWidget 组件
2. 添加一个变量到 State 类来存放 CameraController
3. 添加另外一个变量到 State 类中来存放 CameraController.initialize() 返回的 Future
4. 在 initState() 方法中创建并初始化控制器
5. 在 dispose() 方法中销毁控制器

创建并初始化 CameraController

新建take_photo.dart文件,输入stf快捷创建一个有状态的Widget,命名为TakePictureScreen

class TakePictureScreen extends StatefulWidget {
   
   
  const TakePictureScreen({
   
   super.key, required this.cameras});
  /// 1.接收调用时传入的摄像头列表
  final List<CameraDescription> cameras;

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

class TakePictureScreenState extends State<TakePictureScreen> {
   
   
    /// 2. 相机控制器
    late CameraController _controller;
    /// 3. Future类型存放CameraController初始化返回的Future
    late Future<void> _initializeControllerFuture;
}

在 initState 方法中创建并初始化控制器

class TakePictureScreenState extends State<TakePictureScreen> {
   
   
    /// 根据camera的原生代码,从availableCameras获取可用摄像头列表时,后置索引为0
    /**
    switch device.position {
        case .back:
          lensFacing = .back
        case .front:
          lensFacing = .front
        case .unspecified:
          lensFacing = .external
    ...
    reply.append(cameraDescription)
    */
    int frontCamera = 0; 
    ...
    @override
    void initState() {
   
   
        super.initState();
        /// 设置初始化后置摄像头
        _controller = CameraController(
          widget.cameras[frontCamera],
          /// 清晰度
          ResolutionPreset.medium,
        );
        _initializeControllerFuture = _controller.initialize();
    }
    ...

预览

使用CameraPreview类实现相机的预览

FutureBuilder<void>(
  future: _initializeControllerFuture,