Reputation: 115
I am new to flutter. in my project, there is a various check_list_tile
depending upon the length of the List (attendance list). And I have used one Boolean variable. Now when I press on one checkbox it automatically checks all other checkboxes. Please help me in this (on tap one checkbox should not change the state of all other checkboxes except clicked). I have copied all code please check check_box_list
field.
import 'package:flutter/material.dart';
import 'package:firebase_database/firebase_database.dart';
import 'dart:async';
Map map_student_data;
Iterable iter_student_data,iter_student_key;
List list_student_data,list_student_key;
bool t=true,checkbox=false;
List list;
String validation="yes";
int i;
int year;
final FirebaseDatabase database = FirebaseDatabase.instance;
class IImca_attendence extends StatefulWidget {
@override
_IImca_attendenceState createState() => _IImca_attendenceState();
}
class _IImca_attendenceState extends State<IImca_attendence> {
@override
void initState(){
this.check_year();
super.initState();
}
DateTime date = DateTime.now();
Future check_year()async{
var k= await database.reference().child("NITTE/CLASS/MCA").once().then((DataSnapshot snapshot){
Map sea= snapshot.value;
Iterable iter=sea.keys;
list=iter.toList();
list.sublist(list.length-1);
list.sort();
setState(() {
year=list.length-2;
});
check();
});
}
Future check()async{
var m=await database.reference().child("NITTE/CLASS/MCA/${list[year].toString().toUpperCase()}/STUDENT").once().then((DataSnapshot currentyear){
map_student_data=currentyear.value;
iter_student_data=map_student_data.values;
iter_student_key=map_student_data.keys;
list_student_data=iter_student_data.toList();
list_student_key=iter_student_key.toList();
for(i=0;i<=list_student_data.length;i++){
bool ss=true;
}
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("II-MCA"),
centerTitle: true,
actions: <Widget>[
IconButton(icon: Icon(Icons.refresh),onPressed: (){
setState(() {
check_year();
});
})
],
),
body:
validation=="1"?
new Center(
child: Text("STUDENT DOSE NOT EXIST IN $year",style: TextStyle(color: Colors.grey,fontWeight: FontWeight.bold,fontSize: 20),),
):
new ListView.builder(
itemCount: list_student_data==null?0
:list_student_data.length,
itemBuilder: (BuildContext context,int index){
var student_detail= ['NAME : ${list_student_data[index]['NAME']}','GENDER : ${list_student_data[index]['CURRENT CLASS']}','PHOTO : ${list_student_data[index]['PHOTO']}'];
return new Container(
child: new Center(
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
new Card(
child: new Container(
child: CheckboxListTile(
title: Text("${list_student_key[index]}",style:TextStyle(fontWeight: FontWeight.bold,),),
subtitle: Text("NAME : ${list_student_data[index]['NAME']}"),
value: checkbox,
onChanged: (val){
setState(() {
checkbox=val;
if(checkbox==true){
print("${list_student_data[index]['NAME']}: i am absent");
}if(checkbox==false){
print("${list_student_data[index]['NAME']}: i am present");
}
});
},
),
padding: EdgeInsets.all(5),
),
)
],
),
),
);
}
)
);
}
}
Upvotes: 1
Views: 8382
Reputation: 15012
Well... you are using a global checkbox
variable, so It's quite normal that if you change it, all widget depending on its state will change accordingly.
What I suggest you to do is to add the selected
state inside your model class. Just as an example, assumed you have this Student class (I know you are using firebase, but for sake of time I don't)
class Student {
var name = 'foo';
var year = '2018';
var selected = false;
Student(this.name);
}
This class has is selected
state inside of it.
Now assume that your snapshot give you 3 students. Always for sake of time I've embedded a local array:
class _IImca_attendenceState extends State<IImca_attendence> {
var _students = [Student('foo'), Student('pub'), Student('beer')];
...
(Ellipses are not part of code... ;-])
I suggest you to put your state variables inside the Stateful Widget scope and not onto the Global Scope.
That said you could have:
ListView.builder(
itemCount: _students.length,
itemBuilder: (BuildContext context, int index) {
return new Container(
child: new Center(
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
new Card(
child: new Container(
child: CheckboxListTile(
title: Text(
_students[index].name,
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
subtitle:
Text("NAME : ${_students[index].name}"),
value: _students[index].selected,
onChanged: (val) {
setState(() {
_students[index].selected = val;
if (!_students[index].selected) {
print(
'${_students[index].name}: i am absent');
}
if (_students[index].selected) {
print(
'${_students[index].name}: i am present');
}
});
},
),
padding: EdgeInsets.all(5),
),
)
],
),
),
);
}
)
You should also use an array of bool(s) of the same length of your snapshot data students array... but I'd like to suggest to track this information directly on your Student
model.
UPDATE
As you are more comfortable using array I've change my code using a complementary array of bool
of the same size of your student list.
All you have to do is an array (not a single value) of boolean values, the same size of your student array, lets call this list_student_present
(I instead use list_student_present2
)
At the beginning you initialize this in your check function
a way like that:
list_student_data = iter_student_data.toList();
// This is the array you wanna use (first all false)
list_student_present = iter_student_data.map((_) => false).toList();
And then you will use this array of bool to check the state of your checkboxes:
itemBuilder: (BuildContext context, int index) {
return new Container(
child: new Center(
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
new Card(
child: new Container(
child: CheckboxListTile(
title: Text(
_students[index].name,
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
subtitle:
Text("NAME : ${_students[index].name}"),
value: list_student_present[index],
onChanged: (val) {
setState(() {
list_student_present[index] = val;
if (!list_student_present[index]) {
print(
'${_students[index].name}: i am absent');
}
if (list_student_present[index]) {
print(
'${_students[index].name}: i am present');
}
});
},
),
padding: EdgeInsets.all(5),
),
)
],
),
),
);
}
Do not use my Student class (I continue using it so that I'm able to show you data without firebase), continue using your students array list from your firebase snapshot.
Full code:
import 'package:flutter/material.dart';
import 'dart:async';
Map map_student_data;
Iterable iter_student_data, iter_student_key;
List list_student_data, list_student_key, list_student_present, list_student_present2;
bool t = true;
List list;
String validation = "yes";
int i;
int year;
class Student {
var name = 'foo';
var year = '2018';
var selected = false;
Student(this.name);
}
class IImca_attendence extends StatefulWidget {
@override
_IImca_attendenceState createState() => _IImca_attendenceState();
}
class _IImca_attendenceState extends State<IImca_attendence> {
var _students = [Student('foo'), Student('pub'), Student('beer')];
@override
void initState() {
this.check_year();
super.initState();
}
DateTime date = DateTime.now();
Future check_year() async {
Map sea = {1: 'atlantic', 2: 'pacific'};
Iterable iter = sea.keys;
list = iter.toList();
list.sublist(list.length - 1);
list.sort();
setState(() {
year = list.length - 2;
});
check();
}
Future check() async {
map_student_data = {
0: {'NAME': 'foo', 'CURRENT CLASS': 'pub', 'PHOTO': ''}
};
iter_student_data = map_student_data.values;
iter_student_key = map_student_data.keys;
list_student_data = iter_student_data.toList();
// This is the array you wanna use
list_student_present = iter_student_data.map((_) => false).toList();
// This is the array for my example
list_student_present2 = _students.map((_) => false).toList();
list_student_key = iter_student_key.toList();
for (i = 0; i <= list_student_data.length; i++) {
bool ss = true;
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("II-MCA"),
centerTitle: true,
actions: <Widget>[
IconButton(
icon: Icon(Icons.refresh),
onPressed: () {
setState(() {
check_year();
});
})
],
),
body: validation == "1"
? new Center(
child: Text(
"STUDENT DOSE NOT EXIST IN $year",
style: TextStyle(
color: Colors.grey,
fontWeight: FontWeight.bold,
fontSize: 20),
),
)
: ListView.builder(
itemCount: _students.length,
itemBuilder: (BuildContext context, int index) {
return new Container(
child: new Center(
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
new Card(
child: new Container(
child: CheckboxListTile(
title: Text(
_students[index].name,
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
subtitle:
Text("NAME : ${_students[index].name}"),
value: list_student_present2[index],
onChanged: (val) {
setState(() {
list_student_present2[index] = val;
if (!list_student_present2[index]) {
print(
'${_students[index].name}: i am absent');
}
if (list_student_present2[index]) {
print(
'${_students[index].name}: i am present');
}
});
},
),
padding: EdgeInsets.all(5),
),
)
],
),
),
);
}));
}
}
I really don't like this solution. What I suggest you is to create your PODOs (Plain Old Dart Object) representing your firebase models and deserialise them from your firebase snapshots.
Upvotes: 3