A Flutter plugin for iOS and Android for picking images from the image library, and taking new pictures with the camera.
First, add image_picker
as a dependency in your pubspec.yaml file.
Add the following keys to your Info.plist file, located in <project root>/ios/Runner/Info.plist
:
NSPhotoLibraryUsageDescription
- describe why your app needs permission for the photo library. This is called Privacy - Photo Library Usage Description in the visual editor.NSCameraUsageDescription
- describe why your app needs access to the camera. This is called Privacy - Camera Usage Description in the visual editor.NSMicrophoneUsageDescription
- describe why your app needs access to the microphone, if you intend to record videos. This is called Privacy - Microphone Usage Description in the visual editor.No configuration required - the plugin should work out of the box.
Add android:requestLegacyExternalStorage="true"
as an attribute to the <application>
tag in AndroidManifest.xml. The attribute is false
by default on apps targeting Android Q.
import 'package:image_picker/image_picker.dart';
class MyHomePage extends StatefulWidget {
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
File _image;
final picker = ImagePicker();
Future getImage() async {
final pickedFile = await picker.getImage(source: ImageSource.camera);
setState(() {
_image = File(pickedFile.path);
});
}
@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: getImage,
tooltip: 'Pick Image',
child: Icon(Icons.add_a_photo),
),
);
}
}
Android system -- although very rarely -- sometimes kills the MainActivity after the image_picker finishes. When this happens, we lost the data selected from the image_picker. You can use retrieveLostData
to retrieve the lost data in this situation. For example:
Future<void> retrieveLostData() async {
final LostData response =
await picker.getLostData();
if (response == null) {
return;
}
if (response.file != null) {
setState(() {
if (response.type == RetrieveType.video) {
_handleVideo(response.file);
} else {
_handleImage(response.file);
}
});
} else {
_handleError(response.exception);
}
}
There's no way to detect when this happens, so calling this method at the right place is essential. We recommend to wire this into some kind of start up check. Please refer to the example app to see how we used it.
pickImage
, pickVideo
and LostDataResponse
Starting with version 0.6.7 of the image_picker plugin, the API of the plugin changed slightly to allow for web implementations to exist.
The old methods that returned dart:io
File objects were marked as deprecated, and a new set of methods that return PickedFile
objects were introduced.
ImagePicker
The new ImagePicker API does not rely in static methods anymore, so the first thing you'll need to do is to create a new instance of the plugin where you need it:
final _picker = ImagePicker();
The new methods receive the same parameters as before, but they return a PickedFile
, instead of a File
. The LostDataResponse
class has been replaced by the LostData
class.
Old API | New API |
---|---|
File image = await ImagePicker.pickImage(...) |
PickedFile image = await _picker.getImage(...) |
File video = await ImagePicker.pickVideo(...) |
PickedFile video = await _picker.getVideo(...) |
LostDataResponse response = await ImagePicker.retrieveLostData() |
LostData response = await _picker.getLostData() |
PickedFile
to File
If your app needs dart:io File
objects to operate, you may transform PickedFile
to File
like so:
final pickedFile = await _picker.getImage(...);
final File file = File(pickedFile.path);
You may also retrieve the bytes from the pickedFile directly if needed:
final bytes = await pickedFile.readAsBytes();
Note that on the web platform (kIsWeb == true
), File
is not available, so the path
of the PickedFile
will point to a network resource instead:
if (kIsWeb) {
image = Image.network(pickedFile.path);
} else {
image = Image.file(File(pickedFile.path));
}
Alternatively, the code may be unified at the expense of memory utilization:
image = Image.memory(await pickedFile.readAsBytes())
Take a look at the changes to the example
app introduced in version 0.6.7 to see the migration steps applied there.