flatter:Firebase存储下载url
我是一个新手,我正在尝试制作一个墙纸应用程序,使用Firebase来存储我的图像。该应用程序从Firebase检索图像,用户可以共享图像并将其下载到设备。我正在使用image_gallery_saver软件包,但我无法获取图像的url,因此我可以将其添加到image_gallery_saver功能中。是否有一种简单的方法可以在用户单击特定图像后从firebase获取图像的url 以下是主页:flatter:Firebase存储下载url,firebase,flutter,dart,firebase-storage,Firebase,Flutter,Dart,Firebase Storage,我是一个新手,我正在尝试制作一个墙纸应用程序,使用Firebase来存储我的图像。该应用程序从Firebase检索图像,用户可以共享图像并将其下载到设备。我正在使用image_gallery_saver软件包,但我无法获取图像的url,因此我可以将其添加到image_gallery_saver功能中。是否有一种简单的方法可以在用户单击特定图像后从firebase获取图像的url 以下是主页: import 'package:cardstest2/Screens/ImageScreen.dart'
import 'package:cardstest2/Screens/ImageScreen.dart';
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'dart:async';
class FirestoreListViewPage extends StatefulWidget {
@override
_FirestoreListViewPageState createState() => _FirestoreListViewPageState();
}
class _FirestoreListViewPageState extends State<FirestoreListViewPage> {
Future _data;
Future getPosts() async {
var firestore = Firestore.instance;
QuerySnapshot qn = await firestore.collection("gallery").getDocuments();
return qn.documents;
}
@override
void initState() {
super.initState();
_data = getPosts();
}
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: Text('Subcategories'),
),
body: Container(
child: FutureBuilder(
future: _data,
builder: (_, snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(
child: Text('Waiting...'),
);
} else {
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (_, index){
return Card(
child: ListTile(
title: Image.network(snapshot.data[index].data['GalleryUrl']),
onTap: () {
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => imageScreenPage(snapshot.data[index].data['GalleryUrl']),
),
);
},
),
);
});
}
}),
),
);
}
}
以下是imageScreen页面:
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:share/share.dart';
import 'package:dio/dio.dart';
import 'package:image_gallery_saver/image_gallery_saver.dart';
import 'dart:ui';
class imageScreenPage extends StatefulWidget {
String cardPath;
imageScreenPage(this.cardPath);
@override
_imageScreenPageState createState() => _imageScreenPageState();
}
class _imageScreenPageState extends State<imageScreenPage> {
final LinearGradient backgroundGradient = new LinearGradient(
colors: [new Color(0x10000000), new Color(0x30000000)],
begin: Alignment.topLeft,
end: Alignment.bottomRight);
@override
Widget build(BuildContext context) {
return new Scaffold(
body: new SizedBox.expand(
child: new Container(
decoration: new BoxDecoration(gradient: backgroundGradient),
child: new Stack(
children: <Widget>[
new Align(
alignment: Alignment.center,
child: new Hero(
tag: widget.cardPath,
child: new Image.network(widget.cardPath),
),
),
new Align(
alignment: Alignment.topCenter,
child: new Column(
mainAxisAlignment: MainAxisAlignment.start,
mainAxisSize: MainAxisSize.min,
children: <Widget>[
new AppBar(
elevation: 0.0,
backgroundColor: Colors.transparent,
leading: new IconButton(
icon: new Icon(
Icons.close,
color: Colors.black,
),
onPressed: () => Navigator.of(context).pop()),
)
],
),
),
],
),
),
),
persistentFooterButtons: <Widget>[
IconButton(
icon: Icon(Icons.wallpaper), onPressed: () {},
),
IconButton(
icon: Icon(Icons.file_download), onPressed: () {_save();},
),
IconButton(
icon: Icon(Icons.share), onPressed: () {Share.share(widget.cardPath);},
),
],
);
}
_save() async {
var response = await Dio().get("<insert url>", options: Options(responseType: ResponseType.bytes));
final result = await ImageGallerySaver.saveImage(Uint8List.fromList(response.data));
print(result);
}
}
要获取下载URL,请执行以下操作:
StorageTaskSnapshot snapshot = await storage
.ref()
.child("images/$imageName")
.putFile(file)
.onComplete;
if (snapshot.error == null) {
final String downloadUrl =
await snapshot.ref.getDownloadURL();
}
使用putFile将文件添加到Firebase存储中,然后可以使用snapshot.ref.getDownloadURL获取url。适用于2021年使用flifter的所有用户 这对我有用
import 'package:firebase_storage/firebase_storage.dart' as firebase_storage;
Future<String> uploadImage(imageFile) async {
firebase_storage.Reference ref = storage.ref().child('post_$postId.jpg');
firebase_storage.UploadTask uploadTask = ref.putFile(imageFile);
print('File Uploaded');
var imageUrl = await (await uploadTask).ref.getDownloadURL();
String url = imageUrl.toString();
return url;
}
uploadImage是一个接收imageFile的函数
您必须在异步函数中使用wait uploadImageFile调用它该应用程序不包括用户身份验证,用户也不将图像上载到Firebase。用户只需浏览图像集合,就可以共享图像或将其下载到设备上。这些图像是从Firebase检索的。请使用Firebase的匿名登录,以允许用户通过创建帐户访问存储。这对我来说是不够的…请在回答中添加一些解释