I want to get a download URL from firebase Storage - flutter

Question

here is my build code for getting the URL from firebase storage and showing the image. The image name is save on my firestore as array. So i need to get the list of the image name and turn it into list of URL from firestorage.
#override
Widget build(BuildContext context){
return Container(
child: Stack(
children: [
FutureBuilder<QuerySnapshot>(
future: ref.get(),
builder: (context, snapshot) {
if(snapshot.hasError){
return Scaffold(
body: Center(
child: Text("Error: ${snapshot.error}"),
),
);
}
if(snapshot.connectionState == ConnectionState.done){
return Scaffold(
appBar: AppBar(title: Text("Home"),
centerTitle: true,
),
body: GridView(gridDelegate: const SliverGridDelegateWithMaxCrossAxisExtent(
maxCrossAxisExtent: 200,
childAspectRatio: 2/3,
crossAxisSpacing: 15,
mainAxisSpacing: 15),
children: snapshot.data!.docs.map((document){
DateTime dt = (document['endDateTime'] as Timestamp).toDate();
List im = DownloadURL(document['imageURL']);// this are the call method
return Card(
clipBehavior: Clip.antiAlias,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(15),
),
child:Column(
children: [
Stack(
alignment: Alignment.center,
children: [
Ink.image(
image: NetworkImage(im[0]),
child: InkWell(
onTap: (){
Navigator.of(context).push(MaterialPageRoute(builder: (context)=>DetailScreen(productId: document.id,)));
},
),
height: 170,
fit: BoxFit.cover,
),
],
),
Expanded(
child: Container(
alignment: Alignment.center,
child: Padding(padding: EdgeInsets.all(4).copyWith(bottom: 0),
child: Text("${document['nameP']}",
style: TextStyle(fontSize: 16),
),
),
),
),
// SizedBox(height: 3),
Expanded(
child: Container(
alignment: Alignment.center,
child: Padding(padding: EdgeInsets.all(6).copyWith(bottom: 0),
child: Text("RM ${document['startPrice']}",
style: TextStyle(fontSize: 16),
),
),
),
),
SizedBox(height: 6),
Expanded(child: CountDownText(due: dt,
finishedText: "The Auction has End",
showLabel: true,
daysTextShort: "D ",
hoursTextShort: "H ",
minutesTextShort: "M ",
secondsTextShort: "S ",
style: TextStyle(fontSize: 16,color: Colors.deepPurpleAccent),
),
),
SizedBox(height: 2),
],
),
);
}).toList(),
),
);
}
//loading State
return Scaffold(
body: Center(
child: CircularProgressIndicator(),
),
);
}
),
],
),
);
}
and here is my method for getting the download URL from firebase storage
DownloadURL(List images) async{
List url = [];
for(int i = 0; i<images.length; i++){
url.add(await st.ref('products/${images[i]}').getDownloadURL());
}
return url;
}
it will show error, type 'Future' is not a subtype of type 'List' when run the code.

Answer 1

DownloadURL should return List.
Future<List<String>> DownloadURL(List images) async {
...
}
See Asynchronous programming