Incorrect use of ParentDataWidget. flutter app - flutter

Question

i'm stuck on this problem for long time
in debug console
i don't know how to fix it please help
it says flexible while i did not use flexible widget.
i only used expanded and even when i remove expanded widget still have the same error
also i tried to remove everything except the list view builder widget i sill get the same error
this is the code:
import 'package:flutter/material.dart';
import 'package:todoy/Colors.dart';
import 'Taskslistview.dart';
import 'TasksListTile.dart';
import 'package:provider/provider.dart';
import 'Helper.dart';
bool isChekec = false;
class TasksScreen extends StatelessWidget {
Widget buildsheet(BuildContext context) {
return SingleChildScrollView(
child: Column(
children: [
Container(
decoration: BoxDecoration(
color: Colors.white,
),
height: 400,
child: Padding(
padding: EdgeInsets.only(left: 50.0, right: 50),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
SizedBox(
height: 10,
),
Center(
child: Text(
'Add Task',
style: TextStyle(
fontSize: 30,
color: Provider.of<Helper>(context).choosedcolor),
)),
TextField(
decoration: InputDecoration(
helperStyle: TextStyle(color: Colors.red),
helperText: Provider.of<Helper>(context).alreadyexist
? "this task already exist"
: " "),
textAlign: TextAlign.center,
onChanged: (value) {
if (Provider.of<Helper>(context, listen: false)
.tasknames
.contains(value)) {
Provider.of<Helper>(context, listen: false)
.alreadyture();
} else {
Provider.of<Helper>(context, listen: false)
.alreadyfalse();
}
Provider.of<Helper>(context, listen: false)
.addtaskname(value);
Provider.of<Helper>(context, listen: false)
.addtaskname(value);
print(Provider.of<Helper>(context, listen: false)
.addedtask);
},
),
SizedBox(
height: 10,
),
Container(
height: 50,
// ignore: deprecated_member_use
child: FlatButton(
color: Provider.of<Helper>(context).choosedcolor,
onPressed: () {
if (Provider.of<Helper>(context, listen: false)
.alreadyexist) {
print("you cant");
} else if (Provider.of<Helper>(context, listen: false)
.addedtask ==
"") {
print("ffgg");
} else {
Provider.of<Helper>(context, listen: false).addname(
Provider.of<Helper>(context, listen: false)
.addedtask);
Provider.of<Helper>(context, listen: false)
.add(TasksListTile(
isChcked: isChekec,
nameofthetask:
Provider.of<Helper>(context, listen: false)
.addedtask,
));
Provider.of<Helper>(context, listen: false)
.addedtask = "";
Navigator.pop(context);
}
},
child: Text(
"ADD",
style: TextStyle(color: Colors.white, fontSize: 20),
)),
)
],
),
),
),
],
),
);
}
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
backgroundColor: Provider.of<Helper>(context).choosedcolor,
body: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Padding(
padding: const EdgeInsets.only(left: 300.0, top: 30, right: 15),
child: GestureDetector(
onTap: () {
Navigator.push(context,
MaterialPageRoute(builder: (context) => ColorsScreen()));
},
child: CircleAvatar(
radius: 35,
backgroundColor: Colors.white,
child: Icon(
Icons.invert_colors,
size: 40,
color: Provider.of<Helper>(context).choosedcolor,
)),
),
),
Padding(
padding: EdgeInsets.only(left: 40.0, top: 40),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Padding(
padding: EdgeInsets.only(left: 10.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
CircleAvatar(
radius: 35,
backgroundColor: Colors.white,
child: Icon(
Icons.list,
size: 40,
color: Provider.of<Helper>(context).choosedcolor,
)),
Padding(
padding: const EdgeInsets.only(right: 30.0),
child: Container(
height: 67,
child: FittedBox(
child: FloatingActionButton(
child: Icon(Icons.delete_forever,
size: 40,
color: Provider.of<Helper>(context)
.choosedcolor),
backgroundColor: Colors.white,
onPressed: () {
Provider.of<Helper>(context, listen: false)
.remove();
},
),
),
),
),
],
),
),
Padding(
padding: EdgeInsets.only(top: 8.0, left: 10, bottom: 10),
child: Text(
"Todoy",
style: TextStyle(color: Colors.white, fontSize: 40),
textAlign: TextAlign.start,
),
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Text(
' ${Provider.of<Helper>(context).tasks.length} Tasks',
style: TextStyle(color: Colors.white, fontSize: 40),
textAlign: TextAlign.start,
),
Padding(
padding: const EdgeInsets.only(right: 30.0),
child: Container(
height: 70,
child: FittedBox(
child: FloatingActionButton(
child: Text(
"+",
style: TextStyle(
fontSize: 50,
color: Provider.of<Helper>(context)
.choosedcolor),
),
backgroundColor: Colors.white,
onPressed: () {
showModalBottomSheet(
context: context, builder: buildsheet);
},
),
),
),
),
],
),
],
),
),
SizedBox(
height: 20,
),
Expanded(
child: Container(
padding: EdgeInsets.only(left: 20),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(40),
topRight: Radius.circular(40))),
child: Taskslistview(),
),
),
],
),
),
);
}
}
inside Tasklistview:
class Taskslistview extends StatelessWidget {
#override
Widget build(BuildContext context) {
bool isChecked = false;
return ListView.builder(
itemCount: Provider.of<Helper>(context).tasks.length,
itemBuilder: (context, index) {
return TasksListTile(
isChcked: isChecked,
nameofthetask:
Provider.of<Helper>(context, listen: false).tasknames[index],
);
},
);
}
}
please help i tried everything to fix it nothing worked