flutter unexpected errors - flutter

Question

i am no newbie to the whole thing of being in a circle of errors, bugs and problem solving.
what i have been facing for the last few weeks is the fact that the code works in another laptop, maybe at someone else's project but i get the errors like it doesn't work although i checked and have run the process successfully a few times before.
it had posted, and those errors didn't exist.
we do have a null checker:
child: SingleChildScrollView(
child: isLoading
? Column(
knowing that is Loading is false
and i run android studio.
ps some of the code below feels missing because it has valuable data , and or it would have been longer than what it already is
Widget build(BuildContext context) {
return DefaultTabController(
length: 1,
child: MaterialApp(
theme: ThemeData(fontFamily: 'Harmattan',),
home: Scaffold(
key: _scaffoldKey,
appBar: AppBar(
actions: [
IconButton(onPressed: (){
Navigator.push(
context,
new MaterialPageRoute(
builder: (context) => MaintenanceDataTypesByDriver()));
}, icon: Icon(Icons.view_headline_sharp,size: 40,),)
],
title: Center(child: Text(
'enter',
style: TextStyle(fontSize: 25, color: Colors.white),
),),
leading: Builder(
builder: (BuildContext context) {
return IconButton(
icon: const Icon(
Icons.arrow_back_rounded,
size: 40,
color: Colors.white,
),
onPressed: () {
//Navigator.pushNamed(context, mainScreen.id);
Navigator.push(
context,
new MaterialPageRoute(
builder: (context) => maintenance_screen()));
},
);
},
),
),
body: TabBarView(
children: [
Center(
child: SingleChildScrollView(
child: isLoading
? Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
new CircularProgressIndicator(),
new Text(" اplease hold.. ")
],
)
: new Column(
//crossAxisAlignment: CrossAxisAlignment.stretch,
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
SizedBox(height: 0),
Center(
child: Text(
" choose an option",
style: TextStyle(fontSize: 25,),
),
),
SizedBox(height: 5,),
// Operations Types Api List New /
Container(
height: 75,
width: 400,
decoration: BoxDecoration(
color: Colors.blue.withOpacity(0.35), // border color
borderRadius: BorderRadius.all(Radius.circular(20))
),
child: Center(
child: DropdownButtonHideUnderline(
child: DropdownButton(
style: TextStyle(
fontSize: 20.0,
fontWeight: FontWeight.bold
),),
.........
}).toList(),
onChanged: (String? newVal) {
setState(() {
print(faultReportingName1.toString());
});
},
value: faultReportingName, //pasing the default id that has to be viewed... //i havnt used something ... //you can place some (id)
),
),
),
),
SizedBox(height: 5),
Center(
child: Text(
"press here",
style: TextStyle(fontSize: 25,),
),
),
SizedBox(height: 5,),
// Fault Locations Api List New
Container(
height: 75,
width: 400,
decoration: BoxDecoration(
color: Colors.blue.withOpacity(0.35), // border color
borderRadius: BorderRadius.all(Radius.circular(20))
),
child: Center(
child: DropdownButtonHideUnderline(
child: DropdownButton(
hint: Text("اpress here",
style: TextStyle(
fontSize: 20.0,
fontWeight: FontWeight.bold
),),
.....
style: const TextStyle(
fontSize: 20.0,
fontWeight: FontWeight.bold
),
textAlign : TextAlign.end,
),
...........
},
value: faultLocationsName, //pasing the default id that has to be viewed... //i havnt used something ... //you can place some (id)
),
),
),
),
SizedBox(height: 10),
Center(
child: Text(
" date",
style: TextStyle(fontSize: 25),
),
),
//
Container(
width: 300,
height: 75,
child: TextField(
style: TextStyle(color: Colors.black, fontSize: 20),
onTap: () {
FocusScope.of(context).requestFocus(new FocusNode());
showDatePicker(context: context, initialDate: DateTime.now(), textAlign: TextAlign.center,
decoration: InputDecoration(
errorStyle: TextStyle(height: 0.1),
errorText: _validateStartingDateController ? 'date' : null,
alignLabelWithHint: true,
//labelText: 'Qty',
hintText: '$faultDate1' ,
hintStyle: TextStyle(),
border: OutlineInputBorder(
borderSide:
BorderSide(color: Colors.yellow,
/* 0xfffdbd2a*/width: 20),
borderRadius: BorderRadius.all(Radius.circular(15.0)),
//borderRadius: BorderRadius.circular(15),
),
),
obscureText: false,
//controller: myController,
),
),
//
Center(
child: Text(
"maintenance ",
style: TextStyle(fontSize: 25),
),
),
SizedBox(height: 0),
TextField(
style: TextStyle(fontSize: 20),
keyboardType: TextInputType.number,
//inputFormatters: [FilteringTextInputFormatter.digitsOnly],
controller: opCostController,
textAlign: TextAlign.end,
decoration: InputDecoration(
errorText: _valueValidate ? 'required' : null,
alignLabelWithHint: true,
//labelText: 'Qty',
hintText: 'IQD ',
hintStyle: TextStyle(),
border: OutlineInputBorder(
borderSide:
BorderSide(color: Color(0xfffdbd2a), width: 20),
borderRadius:
BorderRadius.all(Radius.circular(15.0)),
//borderRadius: BorderRadius.circular(15),
),
),
obscureText: false,
//controller: myController,
),
SizedBox(height: 0),
Center(
child: Text(
"notes",
style: TextStyle(fontSize: 25),
),
),
SizedBox(height: 0),
TextField(
style: TextStyle(fontSize: 20),
controller: notesController,
textAlign: TextAlign.end,
decoration: InputDecoration(
errorStyle: TextStyle(height: 1),
alignLabelWithHint: true, hintStyle: TextStyle(),
border: OutlineInputBorder(
borderSide:
BorderSide(color: Color(0xfffdbd2a), width: 20),
borderRadius:
BorderRadius.all(Radius.circular(15.0)),
//borderRadius: BorderRadius.circular(15),
),
),
obscureText: false,
//controller: myController,
),
SizedBox(height: 5),
Center(
child: _file == null ? Text('') :
Container(
height: 310,
margin: EdgeInsets.all(10),
decoration: BoxDecoration(
image: DecorationImage(
fit: BoxFit.fill,
image: FileImage(_file!),
),
borderRadius: BorderRadius.circular(10),
),
//child: Image.asset('images/Logistic.jpg'),
),
),
Container(
height: 50,
width: 200,
child: ElevatedButton(
//style: ElevatedButton.styleFrom(side: BorderSide(width: 1,style: BorderStyle.solid),
style: ButtonStyle(
shape: MaterialStateProperty.all<
RoundedRectangleBorder>(
RoundedRectangleBorder(
borderRadius: BorderRadius.circular(50.0),
side: BorderSide(color: Colors.white)))),
//style: ButtonStyle(shape: OutlinedBorder()),
child: Text(
'save',
style: TextStyle(color: Colors.white, fontSize: 20),
),
onPressed: () {
//if(isLoading)return;
setState(() {
double opCost = double.parse(opCostController.text.trim());
String date = faultDateController.text;
int faultLocID = int.parse(faultLocationsName1!.trim());
int faultRepID = int.parse(faultReportingName1!.trim());
String notes = notesController.text.trim();
if(opCost.isNaN || faultReportingName1=='' || faultLocationsName1=='' ||date =='')
{
print('empty');
return;
}
else{
upload();

Answer 1

I think the problem is coming from your data model class. some of your String values is Null.
Try to check it carefully.