Flutter - 原生交互 - 相册

环境

Flutter 3.29

macOS Sequoia 15.4.1

Xcode 16.3

iOS 13.4.1
iOS 18.5

集成image_picker

在Flutter中可以使用image_picker插件实现从相册中获取图片

添加插件

flutter中访问相册image_picker插件

¥ flutter pub add image_picker
¥ flutter pub get

Xcode工程的GeneratePluginRegistrant新增了对应的注册代码

+ (void)registerWithRegistry:(NSObject<FlutterPluginRegistry>*)registry {
...[FLTImagePickerPlugin registerWithRegistrar:[registry       registrarForPlugin:@"FLTImagePickerPlugin"]];
...
}

更新Xcode的pod依赖

¥ pod update

添加权限

<key>NSPhotoLibraryUsageDescription</key>
<string>需要访问相册以选择图片</string><!-- image_picker也支持直接拍照 -->
<key>NSCameraUsageDescription</key>
<string>需要访问相机用于拍照</string>
<key>NSMicrophoneUsageDescription</key>
<string>需要访问麦克风用于拍摄视频</string>

获取单张照片

可以使用ImagePicker().pickerImage()获取单张图片

else if (index == 2) {_pickImage(ImageSource.gallery),
}

 Future<void> _pickImage(ImageSource source) async {try {// source值可以是相机(camera)或相册(gallery)final pickedFile = await ImagePicker().pickImage(source: source);if (pickedFile != null) {setState(() {if (mounted) {// pop弹窗并返回从相册中选择的图片Navigator.pop(context, pickedFile);}});}} catch (e) {debugPrint("图片选择错误: $e");}}

在上一个界面接收从相册中选择的图片并刷新界面

 floatingActionButton: FloatingActionButton(onPressed: () async {final result = await menuWidget(context: context);if (result != null) {setState(() {_defaultCover = result;});}},backgroundColor: Colors.orangeAccent,child: const Icon(Icons.add, color: Colors.white),
),Future menuWidget({required BuildContext context}) async {return Navigator.push(context,PageRouteBuilder(opaque: false,barrierColor: Colors.black.withValues(alpha: 0.2),pageBuilder:(context, animation, secondaryAnimation) =>PopScope(canPop: true, child: MenuWidget()),transitionsBuilder:(context, animation, secondaryAnimation, child) => SlideTransition(position: Tween<Offset>(begin: const Offset(0.0, 2.4),end: Offset.zero,).animate(animation),child: SlideTransition(position: Tween<Offset>(begin: Offset.zero,end: const Offset(0.0, 2.4),).animate(secondaryAnimation),child: child,),),),);
}

iOS

Andorid

获取多张照片

可以使用ImagePicker().pickMultiImage()获取多张图片

_pickMultiImage(),

Future<void> _pickMultiImage() async {try {// 设置最多获取9张图片final pickedFiles = await ImagePicker().pickMultiImage(limit: 9);if (pickedFiles.isNotEmpty) {setState(() {if (mounted) {Navigator.pop(context, pickedFiles);}});}} catch (e) {debugPrint("图片选择错误: $e");}
}

floatingActionButton: FloatingActionButton(onPressed: () async {final result = await menuWidget(context: context);if (result != null) {setState(() {if (result is XFile) {_defaultCover = result;/// 选择多张照片} else if (result is List<XFile>) {_defaultCover = result[0];}});}},backgroundColor: Colors.orangeAccent,child: const Icon(Icons.add, color: Colors.white),),

选择多张照片在iOS平台上只在14+才生效,用的是PhotosUI.framework中的PHPicker,因为手上测试机是13.4.1设备一直无法多选图片,查看源码

- (void)pickMultiImageWithMaxSize:(nonnull FLTMaxSize *)maxSizequality:(nullable NSNumber *)imageQualityfullMetadata:(BOOL)fullMetadatalimit:(nullable NSNumber *)limitcompletion:(nonnull void (^)(NSArray<NSString *> *_Nullable,FlutterError *_Nullable))completion {[self cancelInProgressCall];FLTImagePickerMethodCallContext *context =[[FLTImagePickerMethodCallContext alloc] initWithResult:completion];context.maxSize = maxSize;context.imageQuality = imageQuality;context.requestFullMetadata = fullMetadata;context.maxImageCount = limit.intValue;if (@available(iOS 14, *)) {[self launchPHPickerWithContext:context];} else {// Camera is ignored for gallery mode, so the value here is arbitrary.[self launchUIImagePickerWithSource:[FLTSourceSpecification makeWithType:FLTSourceTypeGallerycamera:FLTSourceCameraRear]context:context];}
}

limit值传了9,但是launchUIImagePickerWithSource:context:中没有对limit做任何处理代码

- (void)launchUIImagePickerWithSource:(nonnull FLTSourceSpecification *)sourcecontext:(nonnull FLTImagePickerMethodCallContext *)context {UIImagePickerController *imagePickerController = [self createImagePickerController];imagePickerController.modalPresentationStyle = UIModalPresentationCurrentContext;imagePickerController.delegate = self;...

获取视频

使用ImagePicker().pickMedia()可以从相册获取视频文件

Future<void> _pickVideo() async {try {final pickedVideo = await ImagePicker().pickMedia();if (pickedVideo != null) {setState(() {});}} catch (e) {debugPrint("图片选择错误: $e");}
}

获取多媒体文件

使用ImagePicker().pickMultipleMedia()可以从相册获取视频和照片

Future<void> _pickMultiMedia() async {try {final pickedMedia = await ImagePicker().pickMultipleMedia();setState(() {// 页面刷新Navigator.pop(context, pickedMedia);});} catch (e) {debugPrint("图片选择错误: $e");}
}

参考

1. Image Picker plugin for Flutter