image_picker 0.7.0-nullsafety

Flutter plugin for selecting images from the Android and iOS image library, and taking new pictures with the camera.

Image Picker plugin for Flutter

A Flutter plugin for iOS and Android for picking images from the image library, and taking new pictures with the camera.

Installation

First, add image_picker as a dependency in your pubspec.yaml file.

iOS

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.

Android

API < 29

No configuration required - the plugin should work out of the box.

API 29+

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.

Example

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}

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(() {
      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: getImage,
        tooltip: 'Pick Image',
        child: Icon(Icons.add_a_photo),
      ),
    );
  }
}

Handling MainActivity destruction on Android

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.isEmpty) {
    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.

Deprecation warnings in 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.

How to migrate from to ^0.6.7

Instantiate the 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();

Call the new methods

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();

Getting ready for the web platform

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.