Flutter web image_picker未找到实现

Question

我使用版本0.6.7+22的image_picker Flutter软件包从Flutter web应用程序中的设备中拾取图像。我在弹出窗口中调用getImage函数：

class _ImageVerificationPopUpState extends State<ImageVerificationPopUp> {
File _image;
final picker = ImagePicker();
@override
Widget build(BuildContext context) {
return AlertDialog(
title: Text("Upload screenshot"),
content: SizedBox(
width: MediaQuery.of(context).size.width * 0.3,
child: Center(
child: _image != null
? SelectedImage(kIsWeb ? Image.network(_image.path) : Image.file(_image), () {
setState(() {
_image = null;
});
})
: SelectImageButton(_getImage),
),
),
actions: [
TextButton(onPressed: () => Navigator.of(context).pop(), child: Text("Cancel")),
TextButton(
onPressed: () {
final ImageCubit imageCubit = BlocProvider.of<imageCubit>(context);
imageCubit.uploadImage(_image);
Navigator.pop(context);
},
child: Text("Upload"))
],
backgroundColor: Color(0xFF333D81),
);
}
Future<void> _getImage() async {
final PickedFile pickedFile = await picker.getImage(source: ImageSource.gallery);
setState(() {
if (pickedFile != null) {
_image = File(pickedFile.path);
} else {
print("No image selected");
}
});
}
}

在我按下按钮后，它会抛出以下错误：

Error: MissingPluginException(No implementation found for method pickImage on channel plugins.flutter.io/image_picker)
at Object.throw_ [as throw] (http://localhost:7357/dart_sdk.js:5331:11)
at platform_channel.MethodChannel.new._invokeMethod (http://localhost:7357/packages/flutter/src/services/system_channels.dart.lib.js:954:21)
at _invokeMethod.next (<anonymous>)
at http://localhost:7357/dart_sdk.js:39029:33
at _RootZone.runUnary (http://localhost:7357/dart_sdk.js:38886:58)
at _FutureListener.thenAwait.handleValue (http://localhost:7357/dart_sdk.js:33872:29)
at handleValueCallback (http://localhost:7357/dart_sdk.js:34432:49)
at Function._propagateToListeners (http://localhost:7357/dart_sdk.js:34470:17)
at _Future.new.[_completeWithValue] (http://localhost:7357/dart_sdk.js:34312:23)
at async._AsyncCallbackEntry.new.callback (http://localhost:7357/dart_sdk.js:34335:35)
at Object._microtaskLoop (http://localhost:7357/dart_sdk.js:39173:13)
at _startMicrotaskLoop (http://localhost:7357/dart_sdk.js:39179:13)
at http://localhost:7357/dart_sdk.js:34686:9

我已经试过呼叫flutter clean、flutter pub get并重新运行我的应用程序，但无济于事。
我该如何解决这个问题？

提前感谢您的帮助！

Answer 1

尝试将包image_picker_for_web添加到您的pubspec.yaml文件中。

...
dependencies:
...
image_picker: ^0.6.7
image_picker_for_web: ^0.1.0
...
...

然后修改您的getImage方法：

Future<void> _getImage() async {
final PickedFile pickedFile = await picker.getImage(source: ImageSource.gallery);
setState(() {
if (pickedFile != null) {
if (kIsWeb) { // Check if this is a browser session
_image = Image.network(pickedFile.path);
} else {
_image = Image.file(File(pickedFile.path));
}
} else {
print("No image selected");
}
});
}

我想这就是我工作的原因。我收到了和你一样的错误信息。