【发布时间】：2020-04-24 23:00:12
【问题描述】：
图像未显示，但 firebase 数据库中的所有数据都显示在应用程序中。
import 'package:flutter/material.dart';
import 'Authentication.dart';
import 'photoUpload.dart';
import 'Posts.dart';
import 'package:firebase_database/firebase_database.dart';
// import 'package:flutter_blogapp/Authentication.dart';
// import 'package:flutter_blogapp/photoUpload.dart';
class HomePage extends StatefulWidget
{
HomePage
(
{
this.auth,
this.onSignedOut,
}
);
final AuthImplementation auth;
final VoidCallback onSignedOut;
@override
State<StatefulWidget> createState()
{
return _HomePageState();
}
}
class _HomePageState extends State<HomePage>
{
List<Posts> postsList = [];
@override
void initState()
{
super.initState();
DatabaseReference postsRef = FirebaseDatabase.instance.reference().child("Posts");
postsRef.once().then((DataSnapshot snap)
{
var KEYS = snap.value.keys;
var DATA = snap.value;
postsList.clear();
for(var individualKey in KEYS)
{
Posts posts = new Posts
(
DATA[individualKey]['image'],
DATA[individualKey]['description'],
DATA[individualKey]['data'],
DATA[individualKey]['time'],
);
postsList.add(posts);
}
setState(()
{
print('Length : $postsList.length');
});
});
}
void _logoutUser() async
{
try
{
await widget.auth.signOut();
widget.onSignedOut();
}
catch (e)
{
print(e.toString());
}
}
@override
Widget build(BuildContext context)
{
return new Scaffold
(
appBar: new AppBar
(
title: new Text('Home'),
),
body : new Container
(
child: postsList.length == 0 ? new Text(" No Post available ") : new ListView.builder
(
itemCount: postsList.length,
itemBuilder: (_, index)
//itemBuilder: (BuildContext _, int index ) //<-----
{
return PostsUI(postsList[index].image, postsList[index].description, postsList[index].date, postsList[index].time);
}
),
),
bottomNavigationBar: new BottomAppBar
(
color: Colors.pink,
child: new Container
(
margin: const EdgeInsets.only(left: 70.0, right: 70.0),
child: new Row
(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
mainAxisSize: MainAxisSize.max,
children: <Widget>
[
new IconButton
(
icon: new Icon(Icons.local_car_wash),
iconSize: 50,
color: Colors.white,
onPressed: _logoutUser,
),
new IconButton
(
icon: new Icon(Icons.add_a_photo),
iconSize: 50,
color: Colors.white,
onPressed: ()
{
Navigator.push
(
context,
MaterialPageRoute(builder: (context)
{
return new UploadPhotoPage();
})
);
},
),
],
),
),
),
);
}
// Designing Posts UI
Widget PostsUI(String image, String description, String date, String time)
{
return new Card
(
elevation: 10.0,
margin: EdgeInsets.all(15.0),
child: new Container
(
padding: new EdgeInsets.all(14.0),
child: new Column
(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>
[
new Row
(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>
[
new Text
(
date,
style: Theme.of(context).textTheme.subtitle,
textAlign: TextAlign.center,
),
new Text
(
time,
style: Theme.of(context).textTheme.subtitle,
textAlign: TextAlign.center,
), //<----
],
),
SizedBox(height: 10.0,),
new Image.network(image, fit:BoxFit.cover),
SizedBox(height: 10.0,),
new Text
(
description,
style: Theme.of(context).textTheme.subhead,
textAlign: TextAlign.center,
),
],
)
)
);
}
}
显示以下错误：
═══════ 异常被图片资源服务捕获 ════════════════════════════ 抛出以下ArgumentError 解析图像编解码器：无效参数：未指定主机 URI 文件：///图像
当异常被抛出时，这是堆栈
0 _HttpClient._openUrl (dart:_http/http_impl.dart:2276:9)
1 _HttpClient.getUrl (dart:_http/http_impl.dart:2197:48)
2 NetworkImage._loadAsync 包：flutter/…/painting/_network_image_io.dart:84
3 NetworkImage.load 包：flutter/…/painting/_network_image_io.dart:47
4 ImageProvider.resolve...
package:flutter/.../painting/image_provider.dart:327 ... 图片提供者： NetworkImage("image", scale: 1.0) Image key: NetworkImage("image", 规模：1.0）
【问题讨论】：
-
您的图像字段中有什么？您可以调试并查看图像字段的值吗？是否获取正确的url，错误是因为提供的图像字符串无法访问，或者没有加载，尝试调试，查看图像字段的值，并首先在浏览器中尝试该链接
-
你好弗兰克，小时？谢谢你的建议。我已经调试它并在我错的地方得到错误。谢谢
标签： flutter firebase-realtime-database dart