Flutter takePicture() 函数不采用 Flutter 文档中所述的图像路径

Question

我目前正在尝试编写相机应用程序的代码，该应用程序捕获图像并通过单独的小部件显示它。为此，我使用了 Flutter 文档 here。这是完整代码。

    import 'dart:async';
import 'dart:io';

import 'package:camera/camera.dart';
import 'package:flutter/material.dart';
import 'package:path/path.dart' show join;
import 'package:path_provider/path_provider.dart';

Future<void> main() async {
  // Ensure that plugin services are initialized so that `availableCameras()`
  // can be called before `runApp()`
  WidgetsFlutterBinding.ensureInitialized();

  // Obtain a list of the available cameras on the device.
  final cameras = await availableCameras();

  // Get a specific camera from the list of available cameras.
  final firstCamera = cameras.first;

  runApp(
    MaterialApp(
      theme: ThemeData.dark(),
      home: TakePictureScreen(
        // Pass the appropriate camera to the TakePictureScreen widget.
        camera: firstCamera,
      ),
    ),
  );
}

// A screen that allows users to take a picture using a given camera.
class TakePictureScreen extends StatefulWidget {
  final CameraDescription camera;

  const TakePictureScreen({
    Key key,
    @required this.camera,
  }) : super(key: key);

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

class TakePictureScreenState extends State<TakePictureScreen> {
  CameraController _controller;
  Future<void> _initializeControllerFuture;

  @override
  void initState() {
    super.initState();
    // To display the current output from the Camera,
    // create a CameraController.
    _controller = CameraController(
      // Get a specific camera from the list of available cameras.
      widget.camera,
      // Define the resolution to use.
      ResolutionPreset.medium,
    );

    // Next, initialize the controller. This returns a Future.
    _initializeControllerFuture = _controller.initialize();
  }

  @override
  void dispose() {
    // Dispose of the controller when the widget is disposed.
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Take a picture')),
      // Wait until the controller is initialized before displaying the
      // camera preview. Use a FutureBuilder to display a loading spinner
      // until the controller has finished initializing.
      body: FutureBuilder<void>(
        future: _initializeControllerFuture,
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.done) {
            // If the Future is complete, display the preview.
            return CameraPreview(_controller);
          } else {
            // Otherwise, display a loading indicator.
            return Center(child: CircularProgressIndicator());
          }
        },
      ),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.camera_alt),
        // Provide an onPressed callback.
        onPressed: () async {
          // Take the Picture in a try / catch block. If anything goes wrong,
          // catch the error.
          try {
            // Ensure that the camera is initialized.
            await _initializeControllerFuture;

            // Construct the path where the image should be saved using the
            // pattern package.
            final path = join(
              // Store the picture in the temp directory.
              // Find the temp directory using the `path_provider` plugin.
              (await getTemporaryDirectory()).path,
              '${DateTime.now()}.png',
            );

            // Attempt to take a picture and log where it's been saved.
            await _controller.takePicture(path);

            // If the picture was taken, display it on a new screen.
            Navigator.push(
              context,
              MaterialPageRoute(
                builder: (context) => DisplayPictureScreen(imagePath: path),
              ),
            );
          } catch (e) {
            // If an error occurs, log the error to the console.
            print(e);
          }
        },
      ),
    );
  }
}

// A widget that displays the picture taken by the user.
class DisplayPictureScreen extends StatelessWidget {
  final String imagePath;

  const DisplayPictureScreen({Key key, this.imagePath}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Display the Picture')),
      // The image is stored as a file on the device. Use the `Image.file`
      // constructor with the given path to display the image.
      body: Image.file(File(imagePath)),
    );
  }
}

现在 takePicture() 函数应该将 path 作为参数，但事实并非如此。

我应该如何处理这个错误才能正确保存图片，然后获取图片的路径来显示它？

提前致谢！

Answer 1

您的代码将适用于此版本的相机插件

dependencies:
  camera: 0.5.8+17

自版本 0.6.x takePicture 没有参数。如果你想运行它与最新的插件版本，看看当前 example.

Answer 2

有点晚了，但也许这会帮助其他人使用最新的相机版本。控制器 -> takePicture() 方法 return XFile 和 XFile 对象有一个方法 saveTo()

      XFile picture = await controller.takePicture();
      picture.saveTo(filePath);

Flutter takePicture() 函数不采用 Flutter 文档中所述的图像路径

Flutter takePicture() function does not take an image path as stated in the Flutter docs

camera

android-camera

flutter