我在排序卡片 list 时遇到麻烦。每次保存数据时，数据都会以卡的形式输出到我的应用中。它包含名称，时间，日期，图片等。问题是它没有按时间和日期排序。它只是添加和添加。它甚至不堆叠，仅添加到列表中的任何位置。顺便说一句，我通过StreamBuilder获得此数据。谁能帮我解决这个问题？谢谢。
我的StreamBuilder代码:
StreamBuilder<QuerySnapshot>(
stream: db.collection('HELP REQUEST').where('Type_OfDisaster', isEqualTo: '[Drought]').snapshots(),
builder: (context, snapshot) {
if (snapshot.hasData) {
return Column(
children: snapshot.data.documents
.map((doc) => buildItem(doc))
.toList());
}
else {
return Container(
child: Center(
child: CircularProgressIndicator()
)
);
}
});
我在卡中输出数据的位置:
Container buildItem(DocumentSnapshot doc) {
return Container(
child: Padding(
padding: const EdgeInsets.only(left: 20.0, right: 20.0, bottom: 15.0),
child: Card(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(15),
),
color: Color(0xFFFFFFFF),
elevation: 5,
child: Padding(
padding: const EdgeInsets.only(top: 20, left: 20, right: 20),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Row(
children: <Widget> [
picture(),
SizedBox(
width: 10,
),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Row(
children: <Widget>[
Text(
'${doc.data['Name_ofUser']}',
style: TextStyle(
fontSize: 11.5,
fontWeight: FontWeight.w800),
),
],
),
Row(
children: <Widget>[
Text(doc.data['Help_DatePosted'],
style: TextStyle(
fontSize: 9,
fontWeight: FontWeight.w800
),
),
],
)
],
),
Visibility(
visible: orgstat,
child: Padding(
padding: const EdgeInsets.only(left: 8.0, bottom: 5.0),
child: Icon(
FontAwesomeIcons.checkCircle,
color: Colors.green,
size: 12,
),
),
)
],
),
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
CircleAvatar(
radius: 20,
backgroundImage: AssetImage('assets/Drought.jpg')
),
],
),
],
),
Container(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
SizedBox(
height: 20,
),
Padding(
padding: const EdgeInsets.only(top: 8.0),
child: Text('Description:', style: TextStyle(
fontSize: 11.5,
color: Color(0xFF000000)
),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: GestureDetector(
onTap: (){
setState(() {
});
},
child: Text(
'${doc.data['Help_Description']}',
maxLines: 3,
overflow: TextOverflow.ellipsis,
textAlign: TextAlign.justify,
style: TextStyle(
fontSize: 13.5, fontWeight: FontWeight.w800,
color: Color(0xFF000000)),
),
),
),
Row(
children: <Widget>[
Text('Families affected:', style: TextStyle(
fontSize: 11.5,
color: Color(0xFF000000)
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
'${doc.data['Help_FamiliesAffected']}',
maxLines: 1,
overflow: TextOverflow.ellipsis,
style: TextStyle(
fontSize: 13.5, fontWeight: FontWeight.w800,
color: Color(0xFF000000)),
),
),
],
),
Row(
children: <Widget>[
Text('Area/Barangay:', style: TextStyle(
fontSize: 11.5,
color: Color(0xFF000000)
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
'${doc.data['Help_AreaAffected']}',
maxLines: 1,
overflow: TextOverflow.ellipsis,
style: TextStyle(
fontSize: 13.5,
fontWeight: FontWeight.w800,
color: Color(0xFF000000)
),
),
),
],
),
Row(
children: <Widget>[
Text('Things we need:',
style: TextStyle(
fontSize: 11.5,
color: Color(0xFF000000)
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
'${doc.data['Help_ThingsNeeded']}'.replaceAll(new RegExp(r'[^\w\s\,]+'),''),
maxLines: 1,
overflow: TextOverflow.ellipsis,
style: TextStyle(
fontSize: 13.5,
fontWeight: FontWeight.w800,
color: Color(0xFF000000)),
),
),
],
),
Row(
children: <Widget>[
Text('Drop off location:',
style: TextStyle(
fontSize: 11.5,
color: Color(0xFF000000)
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
'${doc.data['Help_DropoffLocation']}',
maxLines: 2,
overflow: TextOverflow.ellipsis,
style: TextStyle(
fontSize: 13.5, fontWeight: FontWeight.w800),
),
),
],
),
Row(
children: <Widget>[
Text('For inquiries call:',
style: TextStyle(
fontSize: 11.5,
color: Color(0xFF000000)
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
'${doc.data['Help_Inquiry']}',
maxLines: 1,
overflow: TextOverflow.ellipsis,
style: TextStyle(
fontSize: 13.5,
fontWeight: FontWeight.w800,
color: Color(0xFF000000)
),
),
),
],
),
],
),
),
Padding(
padding: const EdgeInsets.only(top: 8.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(bottom: 10, top: 15),
child: Container(
height: _height * 0.05,
width: _width * 0.30,
child: Text(
'${doc.data['Respondents_Count'].toString()} respondents.',
style: TextStyle(
color: Color(0xFF000000),
fontSize: 12,
fontWeight: FontWeight.w800,
),
),
),
),
Padding(
padding: const EdgeInsets.only(bottom: 10),
child: Container(
height: _height * 0.05,
width: _width * 0.30,
child: RaisedButton(
highlightColor: Color(0xFF02663B1),
shape: RoundedRectangleBorder(
borderRadius:
BorderRadius.all(Radius.circular(20.0))),
color: Color(0xFF3F6492),
onPressed: () async {
final FirebaseAuth _firebaseAuth = FirebaseAuth.instance;
final FirebaseUser user = await _firebaseAuth.currentUser();
if (user.isEmailVerified){
Navigator.push(
context,
MaterialPageRoute(
builder: (BuildContext context) => DroughtFeedBenefactorAnswerHelp(
doc.data['Help_Description'],
doc.data['Name_ofUser'],
doc.data['User_ID'],
doc.data['Help_DropoffLocation'],
doc.data['Help_ThingsNeeded'],
doc.data['Type_OfDisaster'],
doc.data['Help_AreaAffected'],
doc.data['Unique_ID'],
widget.totalInterestedCount,
widget.totalConfirmedhelpCount,
doc.data['Respondents_Count']
)
)
);
}else{
_showVerifyEmail(doc.data);
}
},
child: Text(
'I want to help',
style: TextStyle(
color: Color(0xFFFFFFFF),
fontSize: 12,
fontWeight: FontWeight.w800),
),
),
),
)
],
),
),
],
),
),
),
),
);
}
卡的用户界面:
最佳答案
您可以使用firestore提供的或方法
https://firebase.google.com/docs/firestore/query-data/order-limit-data
db.collection('HELP REQUEST')
.where('Type_OfDisaster', isEqualTo: '[Drought]')
.orderBy('time', descending: true)
.snapshots()
希望它可以帮助您;)
关于flutter - Flutter:如何按时间和日期对卡片列表进行排序，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/59751542/