File：homepage.dart
class _HomePageState extends State<HomePage> {
var _scaffoldBody;
var _scaffoldTitle;
@override
initState() {
_scaffoldTitle=new Text("Wall");
_scaffoldBody=new Center(child:CircularProgressIndicator());
}
@override
Widget build(BuildContext context) {
return Scaffold(
drawer: new Drawer(
child: ListView(
padding: EdgeInsets.zero,
children: <Widget>[
DrawerHeader(
child: Text('Drawer Header'),
decoration: BoxDecoration(
color:Theme.of(context).accentColor,
),
),
ListTile(
title: Text('Home'),
onTap: () {
setState(() {
_scaffoldTitle=new Text("Home");
_scaffoldBody=new Text("Home Page");
});
Navigator.pop(context);
},
),
ListTile(
title: Text('MenuItem1'),
onTap: () {
setState(() {
_scaffoldTitle=new Text("1st Menu");
_scaffoldBody=new TestPage("Page 1");
});
Navigator.pop(context);
},
),
ListTile(
title: Text('MenuItem2'),
onTap: () {
setState(() {
_scaffoldTitle=new Text("2nd Item");
_scaffoldBody=new TestPage("Page 2");
});
Navigator.pop(context);
},
),
],
),
),
appBar: new AppBar(
title: _scaffoldTitle,
elevation: 2.0,
actions: <Widget>[
],
),
body:_scaffoldBody,
);
}
文件：TestPage.dart
import 'package:flutter/material.dart';
class TestPage extends StatefulWidget{
final String rollNumber;
TestPage(this.rollNumber);
@override
TestPageState createState() => new TestPageState(rollNumber);
}
class TestPageState extends State<TestPage>{
String rollNumber;
TestPageState(this.rollNumber);
@override
Widget build(BuildContext context) {
return new Text(rollNumber);
}
}
输出：
当我从抽屉中选择“主页”时，它显示为“主页”
然后我选择：“ MenuItem1”显示为“ Page 1”
然后我选择：“ MenuItem2”显示相同的“ Page 1”（意外）
然后我选择：“主页”显示为“主页”
然后我选择了“ MenuItem2”，它正确显示为“ Page 2”
然后我选择：“ MenuItem1”显示为“ Page 2”（意外）
无法解决。卡住了！！任何解决方案表示赞赏。在此先感谢！
答案 0 :(得分：0)
如下更新您的TestPart.dart：
import 'package:flutter/material.dart';
class TestPage extends StatefulWidget{
final String rollNumber;
TestPage(this.rollNumber);
@override
TestPageState createState() => new TestPageState();
}
class TestPageState extends State<TestPage>{
@override
Widget build(BuildContext context) {
return new Text(widget.rollNumber);
}
}
答案 1 :(得分：0)
我的StudentPage班
import 'package:flutter/material.dart';
import 'package:firebase_database/firebase_database.dart';
import 'calendar_utils.dart';
import 'dart:async';
final mainReference = FirebaseDatabase.instance.reference();
class StudentPage extends StatefulWidget{
final String rollNumber;
StudentPage(this.rollNumber);
@override
StudentPageState createState() => new StudentPageState(rollNumber);
}
class StudentPageState extends State<StudentPage>{
final String currentRoll,currentYear="2018-19";
StudentPageState(this.currentRoll);
List<String> academicMonth=["June","July","August","September","October","November","December",
"January","February","March","April","May"];
int firstHalfYear=2018,secondHalfYear=2019;
List<Widget> _monthListArray=[new ListTile(title:new Text("Academic Year",style: new TextStyle(fontWeight: FontWeight.bold,fontSize: 20.0),),)];
List<Widget> _listView;
int _no_of_working=0;
int _no_of_present=0;
@override
void initState() {
// TODO: implement initState
_listView=[new Center(
child: new CircularProgressIndicator(),
)];
_loadMonths();
}
@override
Widget build(BuildContext context) {
return new RefreshIndicator(child: new ListView(
children: _listView,
), onRefresh: _loadMonths);
}
Future<Null> _loadMonths() async {
_listView.clear();
await mainReference.child("XXXX").child("attendance").child(
widget.rollNumber).child(currentYear).once().then((
DataSnapshot dataSnapshot) {
try {
int monthIndex=5; //monthIndex starts from June
for(var month in academicMonth){
debugPrint("Month:"+month);
monthIndex=(monthIndex+1)%12; //month index cycles throughout 1-12
if(monthIndex==0) monthIndex=12;
List<Widget> _daysList=[];
_monthListArray.add(new Padding(padding: EdgeInsets.all(16.0),child: new Text(month+" "+(monthIndex<6?secondHalfYear:firstHalfYear).toString(),style: new TextStyle(color: Colors.black87,fontWeight: FontWeight.bold,fontSize: 20.0),),)); //initializing the month
_monthListArray.add(new Padding(padding: EdgeInsets.only(top: 10.0,bottom: 10.0),child:
new Row(children: <Widget>[
new Expanded(
child: new Center(child: new Text("S",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("M",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("T",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("W",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("T",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("F",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("S",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
],),));
debugPrint(monthIndex.toString());
int freeSpace=CalendarUtils(1,monthIndex,monthIndex<6?secondHalfYear:firstHalfYear).getDayFromDate();
debugPrint("FreeSpace---"+freeSpace.toString());
if(freeSpace!=0){
for (var i = 0; i < freeSpace; i++) {
_daysList.add(new Text(""));
}
}
debugPrint(monthIndex.toString());
var year=monthIndex<6?secondHalfYear:firstHalfYear;
debugPrint("Year"+year.toString());
debugPrint("Forloop limit:"+CalendarUtils(1,monthIndex,monthIndex<6?firstHalfYear:secondHalfYear).numberOfDays().toString());
for(var day=1;day<=CalendarUtils(1,monthIndex,monthIndex<6?secondHalfYear:firstHalfYear).numberOfDays();day++){
try {
//debugPrint(day.toString()+":"+dataSnapshot.value[month][day].toString());
if (CalendarUtils(day, monthIndex,
monthIndex < 6 ? secondHalfYear: firstHalfYear)
.getDayFromDate() != 0){
if (dataSnapshot.value[month][day].toString() == "1") {
_no_of_working++;
_no_of_present++;
_daysList.add(
new Padding(padding: EdgeInsets.only(left: 10.0,right: 10.0,top: 2.0,bottom: 2.0),
child: new Container(
alignment: Alignment.center,
width: 30.0,
height: 30.0,
decoration: new BoxDecoration(
borderRadius: new BorderRadius.all(new Radius.circular(50.0)),
color: Colors.green),
child: new Text(
day.toString(),
style: new TextStyle(color: Colors.white),
),
),
)
);
}
else if (dataSnapshot.value[month][day].toString() == "0"){
_no_of_working++;
_daysList.add(
new Padding(padding: EdgeInsets.only(left: 10.0,right: 10.0,top: 2.0,bottom: 2.0),
child: new Container(
alignment: Alignment.center,
width: 30.0,
height: 30.0,
decoration: new BoxDecoration(
borderRadius: new BorderRadius.all(new Radius.circular(50.0)),
color: Colors.redAccent),
child: new Text(
day.toString(),
style: new TextStyle(color: Colors.white),
),
),
)
);
}
else {
_daysList.add(
new Padding(padding: EdgeInsets.only(left: 10.0,right: 10.0,top: 2.0,bottom: 2.0),
child: new Container(
alignment: Alignment.center,
width: 30.0,
height: 30.0,
decoration: new BoxDecoration(
borderRadius: new BorderRadius.all(new Radius.circular(50.0)),
),
child: new Text(
day.toString(),
style: new TextStyle(color: Colors.black),
),
),
)
);
}
}else {
_daysList.add(
new Center(child: new Text(day.toString(), style:
new TextStyle(color: Colors.black45),)));
}
}catch (e){
_daysList.add(new Center(child:new Text(day.toString(),style:
new TextStyle(color: Colors.black),) ));
}
}
Widget _daysGrid=new GridView.count(crossAxisCount: 7,
shrinkWrap: true,
physics: NeverScrollableScrollPhysics(),
childAspectRatio: 1.5,
children: _daysList,
);
_monthListArray.add(_daysGrid);
}
}catch(e){}
_monthListArray.add(new Text((_no_of_present/_no_of_working).toString()));
});
this.setState((){
_listView=_monthListArray;
});
}
}
答案 2 :(得分：0)
我的HomePage.dart
import 'package:flutter/material.dart';
import 'package:smart_school_parent/TestPage.dart';
import 'package:smart_school_parent/attendance.dart';
import 'package:smart_school_parent/post.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:smart_school_parent/auth.dart';
import 'dart:async';
class HomePage extends StatefulWidget {
final BaseAuth auth;
final VoidCallback onSignOut;
HomePage({Key key, this.auth, this.onSignOut}) : super(key: key);
@override
_HomePageState createState() => new _HomePageState(this.auth);
}
class _HomePageState extends State<HomePage> {
final mainReference = FirebaseDatabase.instance.reference();
List<PostData> post_list = new List();
var _scaffoldBody;
var _loading;
var _currentYear;
var _scaffoldTitle;
List<Widget> _childrenList=[new Text("Profiles",textAlign: TextAlign.left,style: new TextStyle(fontWeight: FontWeight.bold),)];
BaseAuth auth;
_HomePageState(this.auth);
@override
initState() {
//_children=updateChildren();
_updateChildren();
getList();
_loading=true ;
_scaffoldTitle=new Text("Wall");
_scaffoldBody=new Center(child:CircularProgressIndicator());
}
@override
Widget build(BuildContext context) {
return Scaffold(
drawer: new Drawer(
child: ListView(
// Important: Remove any padding from the ListView.
padding: EdgeInsets.zero,
children: <Widget>[
DrawerHeader(
child: Text('XXXXx'),
decoration: BoxDecoration(
color:Theme.of(context).accentColor,
),
),
ListTile(
title: Text('Wall'),
onTap: () {
setState(() {
_scaffoldTitle=new Text("Wall");
_scaffoldBody=new RefreshIndicator(child: _loadWall(), onRefresh: getList);
});
Navigator.pop(context);
},
),
Column(
children: _childrenList,
),
],
),
),
appBar: new AppBar(
title: _scaffoldTitle,
elevation: 2.0,
actions: <Widget>[
],
),
body:_scaffoldBody,
);
}
Future <Null> getList() async {
await mainReference.child("NISE-Coimbatore").child("posts").once().then((DataSnapshot dataSnapshot) {
this.setState(() {
post_list.clear();
if(dataSnapshot.value!=null){
for (var value in dataSnapshot.value.values) {
post_list.add(new PostData.fromJson(value));
//debugPrint(value.toString());
}
}else{
this.setState((){
});
}
});
});
setState(() {
_scaffoldBody=new RefreshIndicator(child: _loadWall(), onRefresh: getList);
});
}
Widget _loadWall(){
return Stack(
children: <Widget>[
new ListView.builder(itemBuilder: (BuildContext context,int index){
return new Post(post_list[index].image,post_list[index].title,post_list[index].content);
},
itemCount: post_list == null ? 0 : post_list.length,)
],
);
}
_updateChildren() async {
_currentYear= await mainReference.child("attendance").child("currentYear").once();
await auth.currentUser().then((String userId) async{
mainReference.child("NISE-Coimbatore").child("parents").child(userId).child('children').once().then((DataSnapshot dataSnapshot){
for (var value in dataSnapshot.value){
this.setState((){
_childrenList.add(
new Padding(
padding: EdgeInsets.only(left: 25.0),
child: ListTile(
title: Text(value.toString()),
onTap: () {
super.setState(() {
_scaffoldTitle=new Text(value.toString());
this._scaffoldBody=new StudentPage(value.toString());
});
Navigator.pop(context);
},
),
),
);
});
//debugPrint("Childrrncount::"+value.toString());
}
});
});
}
}
class PostData{
String title;
String content;
String image;
PostData(this.title, this.content, this.image);
PostData.fromJson(var value) {
this.title = value['title'];
this.content = value['content'];
this.image = value['image'];
}
}
_childrenList具有两个元素。 datasnapshot.values具有[15505,15501]两个卷号
firebase的两个滚动号都出现在抽屉框上，并在点击时预期显示StudentPage（15501.tostring（））或StudentPage（15505.tostring（））
如果从抽屉中选择“ Wall”，然后选择任何“ rollNumbers”，则可以按预期工作
如果我从抽屉中的rollNumbers之一切换到其他rollNumber，则无法正常工作。
类似于我的第一篇文章。仅_scaffoldTitle会相应地更改。