FirebaseStorage - how to get all images in a folder-CodePudding

I'm trying to list all images in a created folder in FirebaseStorage.

Future getImages(String folderName) async {
    final docRef = FirebaseStorage.instance.ref().child(folderName);

    List imageRef = [];

    docRef.listAll().then((result) async {
      imageRef = result.items;
    });

    return imageRef;
  }

FutureBuilder:

FutureBuilder(

future: getImages(images.first),
builder: (context, AsyncSnapshot snapshot) {

  if(snapshot.hasData){

    List list = snapshot.data;

    return Image.network(list.first);

  } else {
    return const Center(child: CircularProgressIndicator(),);
  }

}),

I can not return anything from a then() function neither can I use its value outside its body!

I thought about returning a future object and then use it inside my FutureBuilder but again I need to return a widget and I can't do that inside a then() function

CodePudding user response：

Try to use await in getImages to get the list result and return the items like this:

Future<List<Reference>> getImages(String folderName) async {
  final docRef = FirebaseStorage.instance.ref().child(folderName);
  final listResult = await docRef.listAll();
  return Future.value(listResult.items);
}

But if you need the download url of the images, you have to add further code since the above will return a List of Reference, and the getDownloadURL method of Reference is also async. You could try this if you need a list of urls:

Future<List<String>> getImages(String folderName) async {
  final docRef = FirebaseStorage.instance.ref().child(folderName);
  final listResult = await docRef.listAll();
  final urls = <String>[];
  for (var item in listResult.items) {
    urls.add(await item.getDownloadURL());
  }
  return Future.value(urls);
}