android - 如何从相机捕获图像，包括覆盖小部件？

Question

我已经使用camera包创建了一个相机处理程序。结果如下所示：

我希望在捕获的图像中包含除捕获和返回按钮之外的时钟和用户配置文件等叠加层，是否可以这样做？

或者也许我应该使用有条件的屏幕截图而不是使用捕获功能？

提前致谢！

编辑

这是我的camera.dart样子：

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

import 'package:flutter/material.dart';
import 'package:camera/camera.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
import 'package:intl/intl.dart';
import 'package:path_provider/path_provider.dart';

List<CameraDescription> cameras;

class CameraPage extends StatefulWidget {
  final int cameraIdx;
  CameraPage({
    Key key,
    @required this.cameraIdx,
  }) : super(key: key);

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

class _CameraPageState extends State<CameraPage> {
  CameraController controller;
  List cameras;
  int selectedCameraIdx;
  String imagePath;
  String _timeString;
  Timer _timer;

  void _getTime() {
    final DateTime now = DateTime.now();
    final String formattedDateTime = _formatDateTime(now);
    setState(() {
      _timeString = formattedDateTime;
    });
  }

  String _formatDateTime(DateTime dateTime) =>
      DateFormat('HH:mm:ss').format(dateTime);

  String timestamp() => DateTime.now().millisecondsSinceEpoch.toString();

// Initialize camera controller
  Future _initCameraController(CameraDescription cameraDescription) async {
    if (controller != null) {
      await controller.dispose();
    }

    // set controller by the camera description with high resolution preset
    controller = CameraController(cameraDescription, ResolutionPreset.high);

    // If the controller is updated then update the UI.
    controller.addListener(() {
      // when this widget is mounted clear the state
      if (this.mounted) {
        setState(() {});
      }

      if (controller.value.hasError) {
        print('Camera error ${controller.value.errorDescription}');
      }
    });

    // 6
    try {
      await controller.initialize();
    } on CameraException catch (e) {
      print(e);
    }

    if (this.mounted) {
      setState(() {});
    }
  }

  Future<String> takePicture() async {
    if (!controller.value.isInitialized) {
      return null;
    }
    final Directory extDir = await getExternalStorageDirectory();
    final String dirPath = '${extDir.path}/Pictures/flutter_test';
    await Directory(dirPath).create(recursive: true);
    final String filePath = '$dirPath/${timestamp()}.jpg';

    if (controller.value.isTakingPicture) {
      // A capture is already pending, do nothing.
      return null;
    }

    try {
      await controller.takePicture(filePath);
    } on CameraException catch (e) {
      _showCameraException(e);
      return null;
    }
    return filePath;
  }

  void logError(String code, String message) =>
      print('Error: $code\nError Message: $message');

  void _showCameraException(CameraException e) {
    logError(e.code, e.description);
  }

  void onCaptureButtonPressed() {
    takePicture().then((String filePath) {
      print(filePath);
      if (mounted) {
        setState(() {
          imagePath = filePath;
        });
      }
    });
  }

  @override
  void initState() {
    super.initState();
    // Check if camera available
    availableCameras().then((availableCameras) {
      cameras = availableCameras;
      if (cameras.length > 0) {
        setState(() {
          // Select front camera as default
          if (widget.cameraIdx != null) {
            selectedCameraIdx = widget.cameraIdx;
          } else {
            selectedCameraIdx = 1;
          }
        });

        _initCameraController(cameras[selectedCameraIdx]).then((void v) {});
      } else {
        print("No camera available");
      }
    }).catchError((err) {
      // Print error if any
      print('Error: $err.code\nError Message: $err.message');
    });

    _timeString = _formatDateTime(DateTime.now());
    _timer = Timer.periodic(Duration(seconds: 1), (Timer t) => _getTime());
  }

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

  @override
  Widget build(BuildContext context) {
    final size = MediaQuery.of(context).size;
    final deviceRatio = size.width / size.height;

    if (!controller.value.isInitialized) {
      return Container();
    }

    return Scaffold(
      body: Stack(
        children: <Widget>[
          Transform.scale(
            scale: controller.value.aspectRatio / deviceRatio,
            child: Center(
              child: AspectRatio(
                aspectRatio: controller.value.aspectRatio,
                child: CameraPreview(controller),
              ),
            ),
          ),
          Align(
            alignment: Alignment.topCenter,
            child: Container(
              width: double.infinity,
              height: 110.0,
              padding: EdgeInsets.only(right: 20.0),
              child: Padding(
                padding: EdgeInsets.only(top: 40.0, right: 0.0),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: <Widget>[
                    GestureDetector(
                      child: Padding(
                        padding: EdgeInsets.only(left: 20.0),
                        child: Icon(
                          FontAwesomeIcons.arrowLeft,
                          color: Colors.white,
                          size: 30.0,
                        ),
                      ),
                      onTap: () {
                        Navigator.of(context).pop();
                      },
                    ),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.end,
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: <Widget>[
                        Padding(
                          padding: EdgeInsets.only(top: 15.0, right: 10.0),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.end,
                            children: <Widget>[
                              Text('Donny Pratama',
                                  style: TextStyle(
                                      color: Colors.white,
                                      fontWeight: FontWeight.bold,
                                      fontSize: 16.0)),
                              Text(
                                'Front End Developer',
                                style: TextStyle(color: Colors.white),
                              )
                            ],
                          ),
                        ),
                        CircleAvatar(
                          radius: 30.0,
                          backgroundImage:
                              NetworkImage('https://via.placeholder.com/150'),
                          backgroundColor: Colors.transparent,
                        )
                      ],
                    ),
                  ],
                ),
              ),
            ),
          ),
          Align(
            alignment: Alignment.bottomLeft,
            child: Container(
              width: double.infinity,
              height: 180.0,
              padding: EdgeInsets.only(left: 20.0),
              child: Align(
                alignment: Alignment.topLeft,
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: <Widget>[
                    Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: <Widget>[
                        Text(
                          _timeString,
                          style: TextStyle(
                            color: Colors.white,
                            fontSize: 50.0,
                            fontFamily: 'Roboto',
                          ),
                        ),
                        Row(
                          children: <Widget>[
                            Padding(
                              padding: EdgeInsets.only(right: 5.0),
                              child: Icon(
                                FontAwesomeIcons.mapMarkerAlt,
                                color: Colors.white,
                                size: 12.0,
                              ),
                            ),
                            Text(
                              'Yogyakarta, Indonesia',
                              style: TextStyle(color: Colors.white),
                            )
                          ],
                        ),
                      ],
                    ),
                  ],
                ),
              ),
            ),
          ),
          Align(
            alignment: Alignment.bottomCenter,
            child: Container(
              width: double.infinity,
              height: 120.0,
              // color: Colors.white,
              padding: EdgeInsets.all(20.0),
              child: Stack(
                children: <Widget>[
                  Align(
                    alignment: Alignment.center,
                    child: SizedBox(
                      width: double.infinity,
                      height: 60.0,
                      child: RaisedButton(
                        elevation: 0.5,
                        color: Colors.orange,
                        textColor: Colors.white,
                        child: Icon(FontAwesomeIcons.camera),
                        shape: RoundedRectangleBorder(
                          borderRadius: BorderRadius.circular(10.0),
                        ),
                        onPressed: onCaptureButtonPressed,
                      ),
                    ),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}

标签： androidflutter