Flutter图片选择插件image_picker_tizen的使用

发布于 1周前 作者 zlyuanteng 来自 Flutter

Flutter图片选择插件image_picker_tizen的使用

image_picker_tizen 是 image_picker 插件的 Tizen 实现版本。它允许在支持 Tizen 的设备上选择图片或视频。

使用方法

要使用此插件，首先需要在 pubspec.yaml 文件中添加以下依赖项：

dependencies:
  image_picker: ^1.0.1
  image_picker_tizen: ^2.3.0

然后，在 Dart 代码中导入 image_picker：

import 'package:image_picker/image_picker.dart';

final ImagePicker picker = ImagePicker();
final XFile? image = await picker.pickImage(source: ImageSource.gallery);

有关详细的使用说明，请参阅 Flutter Image Picker 文档。

支持的设备

目前，image_picker_tizen 支持以下设备：

  • Galaxy Watch 系列（运行 Tizen 5.5 或更高版本）

支持的 API

  • ✅ <code>ImagePicker.pickImage</code> （仅支持 <code>ImageSource.gallery</code> 作为 <code>source</code>）
  • ✅ <code>ImagePicker.pickMultiImage</code>
  • ✅ <code>ImagePicker.pickMedia</code>
  • ❌ <code>ImagePicker.pickVideo</code> （由于缺乏文件管理应用）
  • ❌ <code>ImagePicker.retrieveLostData</code> （仅适用于 Android）
  • ✅ <code>ImagePicker.supportsImageSource</code> （仅支持 <code>ImageSource.gallery</code> 作为 <code>source</code>）

必需的权限

要在应用程序中使用此插件，您需要在 tizen-manifest.xml 文件中声明以下权限：

<privileges>
  <privilege>http://tizen.org/privilege/mediastorage</privilege>
  <privilege>http://tizen.org/privilege/appmanager.launch</privilege>
</privileges>

完整示例代码

以下是一个完整的示例代码，展示了如何使用 image_picker_tizen 插件来选择图片或视频。

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// ignore_for_file: public_member_api_docs

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

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:mime/mime.dart';
import 'package:video_player/video_player.dart';

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

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

  [@override](/user/override)
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: 'Image Picker Demo',
      home: MyHomePage(title: 'Image Picker Example'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, this.title});

  final String? title;

  [@override](/user/override)
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List<XFile>? _mediaFileList;

  void _setImageFileListFromFile(XFile? value) {
    _mediaFileList = value == null ? null : <XFile>[value];
  }

  dynamic _pickImageError;
  bool isVideo = false;

  VideoPlayerController? _controller;
  VideoPlayerController? _toBeDisposed;
  String? _retrieveDataError;

  final ImagePicker _picker = ImagePicker();
  final TextEditingController maxWidthController = TextEditingController();
  final TextEditingController maxHeightController = TextEditingController();
  final TextEditingController qualityController = TextEditingController();

  Future<void> _playVideo(XFile? file) async {
    if (file != null && mounted) {
      await _disposeVideoController();
      late VideoPlayerController controller;
      if (kIsWeb) {
        // TODO(gabrielokura): remove the ignore once the issue is resolved.
        controller = VideoPlayerController.network(file.path);
      } else {
        controller = VideoPlayerController.file(File(file.path));
      }
      _controller = controller;
      const double volume = kIsWeb ? 0.0 : 1.0;
      await controller.setVolume(volume);
      await controller.initialize();
      await controller.setLooping(true);
      await controller.play();
      setState(() {});
    }
  }

  Future<void> _onImageButtonPressed(
    ImageSource source, {
    required BuildContext context,
    bool isMultiImage = false,
    bool isMedia = false,
  }) async {
    if (_controller != null) {
      await _controller!.setVolume(0.0);
    }
    if (context.mounted) {
      if (isVideo) {
        final XFile? file = await _picker.pickVideo(
            source: source, maxDuration: const Duration(seconds: 10));
        await _playVideo(file);
      } else if (isMultiImage) {
        await _displayPickImageDialog(context,
            (double? maxWidth, double? maxHeight, int? quality) async {
          try {
            final List<XFile> pickedFileList = isMedia
                ? await _picker.pickMultipleMedia(
                    maxWidth: maxWidth,
                    maxHeight: maxHeight,
                    imageQuality: quality,
                  )
                : await _picker.pickMultiImage(
                    maxWidth: maxWidth,
                    maxHeight: maxHeight,
                    imageQuality: quality,
                  );
            setState(() {
              _mediaFileList = pickedFileList;
            });
          } catch (e) {
            setState(() {
              _pickImageError = e;
            });
          }
        });
      } else if (isMedia) {
        await _displayPickImageDialog(context,
            (double? maxWidth, double? maxHeight, int? quality) async {
          try {
            final List<XFile> pickedFileList = [];
            final XFile? media = await _picker.pickMedia(
              maxWidth: maxWidth,
              maxHeight: maxHeight,
              imageQuality: quality,
            );
            if (media != null) {
              pickedFileList.add(media);
              setState(() {
                _mediaFileList = pickedFileList;
              });
            }
          } catch (e) {
            setState(() {
              _pickImageError = e;
            });
          }
        });
      } else {
        await _displayPickImageDialog(context,
            (double? maxWidth, double? maxHeight, int? quality) async {
          try {
            final XFile? pickedFile = await _picker.pickImage(
              source: source,
              maxWidth: maxWidth,
              maxHeight: maxHeight,
              imageQuality: quality,
            );
            setState(() {
              _setImageFileListFromFile(pickedFile);
            });
          } catch (e) {
            setState(() {
              _pickImageError = e;
            });
          }
        });
      }
    }
  }

  [@override](/user/override)
  void deactivate() {
    if (_controller != null) {
      _controller!.setVolume(0.0);
      _controller!.pause();
    }
    super.deactivate();
  }

  [@override](/user/override)
  void dispose() {
    _disposeVideoController();
    maxWidthController.dispose();
    maxHeightController.dispose();
    qualityController.dispose();
    super.dispose();
  }

  Future<void> _disposeVideoController() async {
    if (_toBeDisposed != null) {
      await _toBeDisposed!.dispose();
    }
    _toBeDisposed = _controller;
    _controller = null;
  }

  Widget _previewVideo() {
    final Text? retrieveError = _getRetrieveErrorWidget();
    if (retrieveError != null) {
      return retrieveError;
    }
    if (_controller == null) {
      return const Text(
        'You have not yet picked a video',
        textAlign: TextAlign.center,
      );
    }
    return Padding(
      padding: const EdgeInsets.all(10.0),
      child: AspectRatioVideo(_controller),
    );
  }

  Widget _previewImages() {
    final Text? retrieveError = _getRetrieveErrorWidget();
    if (retrieveError != null) {
      return retrieveError;
    }
    if (_mediaFileList != null) {
      return Semantics(
        label: 'image_picker_example_picked_images',
        child: ListView.builder(
          key: UniqueKey(),
          itemBuilder: (BuildContext context, int index) {
            final String? mime = lookupMimeType(_mediaFileList![index].path);

            return Semantics(
              label: 'image_picker_example_picked_image',
              child: kIsWeb
                  ? Image.network(_mediaFileList![index].path)
                  : (mime == null || mime.startsWith('image/')
                      ? Image.file(
                          File(_mediaFileList![index].path),
                          errorBuilder: (BuildContext context, Object error,
                              StackTrace? stackTrace) {
                            return const Center(
                                child:
                                    Text('This image type is not supported'));
                          },
                        )
                      : _buildInlineVideoPlayer(index)),
            );
          },
          itemCount: _mediaFileList!.length,
        ),
      );
    } else if (_pickImageError != null) {
      return Text(
        'Pick image error: $_pickImageError',
        textAlign: TextAlign.center,
      );
    } else {
      return const Text(
        'You have not yet picked an image.',
        textAlign: TextAlign.center,
      );
    }
  }

  Widget _buildInlineVideoPlayer(int index) {
    final VideoPlayerController controller =
        VideoPlayerController.file(File(_mediaFileList![index].path));
    const double volume = kIsWeb ? 0.0 : 1.0;
    controller.setVolume(volume);
    controller.initialize();
    controller.setLooping(true);
    controller.play();
    return Center(child: AspectRatioVideo(controller));
  }

  Widget _handlePreview() {
    if (isVideo) {
      return _previewVideo();
    } else {
      return _previewImages();
    }
  }

  Future<void> retrieveLostData() async {
    final LostDataResponse response = await _picker.retrieveLostData();
    if (response.isEmpty) {
      return;
    }
    if (response.file != null) {
      if (response.type == RetrieveType.video) {
        isVideo = true;
        await _playVideo(response.file);
      } else {
        isVideo = false;
        setState(() {
          if (response.files == null) {
            _setImageFileListFromFile(response.file);
          } else {
            _mediaFileList = response.files;
          }
        });
      }
    } else {
      _retrieveDataError = response.exception!.code;
    }
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title!),
      ),
      body: Center(
        child: !kIsWeb && defaultTargetPlatform == TargetPlatform.android
            ? FutureBuilder<void>(
                future: retrieveLostData(),
                builder: (BuildContext context, AsyncSnapshot<void> snapshot) {
                  switch (snapshot.connectionState) {
                    case ConnectionState.none:
                    case ConnectionState.waiting:
                      return const Text(
                        'You have not yet picked an image.',
                        textAlign: TextAlign.center,
                      );
                    case ConnectionState.done:
                      return _handlePreview();
                    case ConnectionState.active:
                      if (snapshot.hasError) {
                        return Text(
                          'Pick image/video error: ${snapshot.error}}',
                          textAlign: TextAlign.center,
                        );
                      } else {
                        return const Text(
                          'You have not yet picked an image.',
                          textAlign: TextAlign.center,
                        );
                      }
                  }
                },
              )
            : _handlePreview(),
      ),
      floatingActionButton: Column(
        mainAxisAlignment: MainAxisAlignment.end,
        children: <Widget>[
          Semantics(
            label: 'image_picker_example_from_gallery',
            child: FloatingActionButton(
              onPressed: () {
                isVideo = false;
                _onImageButtonPressed(ImageSource.gallery, context: context);
              },
              heroTag: 'image0',
              tooltip: 'Pick Image from gallery',
              child: const Icon(Icons.photo),
            ),
          ),
          Padding(
            padding: const EdgeInsets.only(top: 16.0),
            child: FloatingActionButton(
              onPressed: () {
                isVideo = false;
                _onImageButtonPressed(
                  ImageSource.gallery,
                  context: context,
                  isMultiImage: true,
                  isMedia: true,
                );
              },
              heroTag: 'multipleMedia',
              tooltip: 'Pick Multiple Media from gallery',
              child: const Icon(Icons.photo_library),
            ),
          ),
          Padding(
            padding: const EdgeInsets.only(top: 16.0),
            child: FloatingActionButton(
              onPressed: () {
                isVideo = false;
                _onImageButtonPressed(
                  ImageSource.gallery,
                  context: context,
                  isMedia: true,
                );
              },
              heroTag: 'media',
              tooltip: 'Pick Single Media from gallery',
              child: const Icon(Icons.photo_library),
            ),
          ),
          Padding(
            padding: const EdgeInsets.only(top: 16.0),
            child: FloatingActionButton(
              onPressed: () {
                isVideo = false;
                _onImageButtonPressed(
                  ImageSource.gallery,
                  context: context,
                  isMultiImage: true,
                );
              },
              heroTag: 'image1',
              tooltip: 'Pick Multiple Image from gallery',
              child: const Icon(Icons.photo_library),
            ),
          ),
          if (_picker.supportsImageSource(ImageSource.camera))
            Padding(
              padding: const EdgeInsets.only(top: 16.0),
              child: FloatingActionButton(
                onPressed: () {
                  isVideo = false;
                  _onImageButtonPressed(ImageSource.camera, context: context);
                },
                heroTag: 'image2',
                tooltip: 'Take a Photo',
                child: const Icon(Icons.camera_alt),
              ),
            ),
          Padding(
            padding: const EdgeInsets.only(top: 16.0),
            child: FloatingActionButton(
              backgroundColor: Colors.red,
              onPressed: () {
                isVideo = true;
                _onImageButtonPressed(ImageSource.gallery, context: context);
              },
              heroTag: 'video0',
              tooltip: 'Pick Video from gallery',
              child: const Icon(Icons.video_library),
            ),
          ),
          if (_picker.supportsImageSource(ImageSource.camera))
            Padding(
              padding: const EdgeInsets.only(top: 16.0),
              child: FloatingActionButton(
                backgroundColor: Colors.red,
                onPressed: () {
                  isVideo = true;
                  _onImageButtonPressed(ImageSource.camera, context: context);
                },
                heroTag: 'video1',
                tooltip: 'Take a Video',
                child: const Icon(Icons.videocam),
              ),
            ),
        ],
      ),
    );
  }

  Text? _getRetrieveErrorWidget() {
    if (_retrieveDataError != null) {
      final Text result = Text(_retrieveDataError!);
      _retrieveDataError = null;
      return result;
    }
    return null;
  }

  Future<void> _displayPickImageDialog(
      BuildContext context, OnPickImageCallback onPick) async {
    return showDialog(
        context: context,
        builder: (BuildContext context) {
          return AlertDialog(
            title: const Text('Add optional parameters'),
            content: Column(
              children: <Widget>[
                TextField(
                  controller: maxWidthController,
                  keyboardType:
                      const TextInputType.numberWithOptions(decimal: true),
                  decoration: const InputDecoration(
                      hintText: 'Enter maxWidth if desired'),
                ),
                TextField(
                  controller: maxHeightController,
                  keyboardType:
                      const TextInputType.numberWithOptions(decimal: true),
                  decoration: const InputDecoration(
                      hintText: 'Enter maxHeight if desired'),
                ),
                TextField(
                  controller: qualityController,
                  keyboardType: TextInputType.number,
                  decoration: const InputDecoration(
                      hintText: 'Enter quality if desired'),
                ),
              ],
            ),
            actions: <Widget>[
              TextButton(
                child: const Text('CANCEL'),
                onPressed: () {
                  Navigator.of(context).pop();
                },
              ),
              TextButton(
                  child: const Text('PICK'),
                  onPressed: () {
                    final double? width = maxWidthController.text.isNotEmpty
                        ? double.parse(maxWidthController.text)
                        : null;
                    final double? height = maxHeightController.text.isNotEmpty
                        ? double.parse(maxHeightController.text)
                        : null;
                    final int? quality = qualityController.text.isNotEmpty
                        ? int.parse(qualityController.text)
                        : null;
                    onPick(width, height, quality);
                    Navigator.of(context).pop();
                  }),
            ],
          );
        });
  }
}

typedef OnPickImageCallback = void Function(
    double? maxWidth, double? maxHeight, int? quality);

class AspectRatioVideo extends StatefulWidget {
  const AspectRatioVideo(this.controller, {super.key});

  final VideoPlayerController? controller;

  [@override](/user/override)
  AspectRatioVideoState createState() => AspectRatioVideoState();
}

class AspectRatioVideoState extends State<AspectRatioVideo> {
  VideoPlayerController? get controller => widget.controller;
  bool initialized = false;

  void _onVideoControllerUpdate() {
    if (!mounted) {
      return;
    }
    if (initialized != controller!.value.isInitialized) {
      initialized = controller!.value.isInitialized;
      setState(() {});
    }
  }

  [@override](/user/override)
  void initState() {
    super.initState();
    controller!.addListener(_onVideoControllerUpdate);
  }

  [@override](/user/override)
  void dispose() {
    controller!.removeListener(_onVideoControllerUpdate);
    super.dispose();
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    if (initialized) {
      return Center(
        child: AspectRatio(
          aspectRatio: controller!.value.aspectRatio,
          child: VideoPlayer(controller!),
        ),
      );
    } else {
      return Container();
    }
  }
}

更多关于Flutter图片选择插件image_picker_tizen的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html

1 回复

更多关于Flutter图片选择插件image_picker_tizen的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html


image_picker_tizen 是一个为 Tizen 平台设计的 Flutter 插件，用于从设备中选择图片。它基于 image_picker 插件，但专门为 Tizen 设备进行了适配。以下是如何使用 image_picker_tizen 插件的步骤：

1. 添加依赖

首先，在 pubspec.yaml 文件中添加 image_picker_tizen 依赖：

dependencies:
  flutter:
    sdk: flutter
  image_picker_tizen: ^1.0.0

然后运行 flutter pub get 来安装依赖。

2. 导入插件

在你的 Dart 文件中导入 image_picker_tizen 插件：

import 'package:image_picker_tizen/image_picker_tizen.dart';

3. 使用插件选择图片

你可以使用 ImagePickerTizen 类来从设备中选择图片。以下是一个简单的示例，展示如何从相册中选择图片：

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  File? _image;

  Future<void> _pickImage() async {
    final imagePicker = ImagePickerTizen();
    final pickedFile = await imagePicker.pickImage(source: ImageSource.gallery);

    setState(() {
      if (pickedFile != null) {
        _image = File(pickedFile.path);
      } else {
        print('No image selected.');
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Image Picker Example'),
      ),
      body: Center(
        child: _image == null
            ? Text('No image selected.')
            : Image.file(_image!),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _pickImage,
        tooltip: 'Pick Image',
        child: Icon(Icons.add_a_photo),
      ),
    );
  }
}

4. 处理权限

在 Tizen 设备上，访问相册可能需要特定的权限。确保你在 tizen-manifest.xml 文件中添加了必要的权限声明。例如：

<privileges>
  <privilege>http://tizen.org/privilege/mediastorage</privilege>
</privileges>

5. 运行应用

确保你的 Tizen 设备已连接到开发环境，然后运行应用：

flutter run -d tizen

6. 其他功能

image_picker_tizen 还支持从相机拍照等功能。你可以通过更改 ImageSource 来切换不同的图像源：

final pickedFile = await imagePicker.pickImage(source: ImageSource.camera);
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