Flutter Load Image from Firebase Storage

Here's an example of a stateful widget that loads an image from Firebase Storage object and builds an Image object:

class _MyHomePageState extends State<MyHomePage> {

  final FirebaseStorage storage = FirebaseStorage(
      app: Firestore.instance.app,
      storageBucket: 'gs://my-project.appspot.com');

  Uint8List imageBytes;
  String errorMsg;

  _MyHomePageState() {
      storage.ref().child('selfies/me2.jpg').getData(10000000).then((data) =>
                setState(() {
                  imageBytes = data;
                })
        ).catchError((e) =>
                setState(() {
                  errorMsg = e.error;
                })
        );
  }

  @override
  Widget build(BuildContext context) {
    var img = imageBytes != null ? Image.memory(
        imageBytes,
        fit: BoxFit.cover,
      ) : Text(errorMsg != null ? errorMsg : "Loading...");

    return new Scaffold(
        appBar: new AppBar(
          title: new Text(widget.title),
        ),
        body: new ListView(
          children: <Widget>[
            img,
          ],
        ));
  }
}

Note that FirebaseApp initialization is handled by the Firestore class, so no further initialization code is necessary.

To view the images inside your storage, what you need is the name of the file in the storage. Once you've the file name for the specific image you need. In my case if i want the testimage to be loaded,

final ref = FirebaseStorage.instance.ref().child('testimage');
// no need of the file extension, the name will do fine.
var url = await ref.getDownloadURL();
print(url);

Once you've the url,

Image.network(url);

That's all :)

New alternative answer based on one of the comments.

I don't see anywhere google is charging extra money for downloadURL. So if you're posting some comments please attach a link to it.

Once you upload a file to storage, make that filename unique and save that name somewhere in firestore, or realtime database.

getAvatarUrlForProfile(String imageFileName) async {
final FirebaseStorage firebaseStorage = FirebaseStorage(
    app: Firestore.instance.app,
    storageBucket: 'gs://your-firebase-app-url.com');

Uint8List imageBytes;
await firebaseStorage
    .ref()
    .child(imageFileName)
    .getData(100000000)
    .then((value) => {imageBytes = value})
    .catchError((error) => {});
return imageBytes;
}

Uint8List avatarBytes =
    await FirebaseServices().getAvatarUrlForProfile(userId);

and use it like,

MemoryImage(avatarBytes)

update

In newer versions use

await ref.getDownloadURL();

See How to get full downloadUrl from UploadTaskSnapshot in Flutter?

original

someMethod() async {
  var data = await FirebaseStorage.instance.ref().child("foo$rand.txt").getData();
  var text = new String.fromCharCodes(data);
  print(data);
}

see Download an image from Firebase to Flutter

or

final uploadTask = imageStore.putFile(imageFile);
final url = (await uploadTask.future).downloadUrl;

In the later case you'd need to store the downloadUrl somewhere and then use NetworkImage or similar to get it rendered.