How to change a variable when changing DropDownButton - flutter

Question

I have 3 variables containing text that I can pass to message.
String easyDrop = 'All ok';
String mediumDrop = '1 problem';
String hardDrop = 'All not ok';
message: easyDrop ,
I would like to change them depending on the state of my DropDownButton. How can I do this?
import 'package:flutter/material.dart';
class DropDownButtonDifficultySettingsWidget extends StatefulWidget {
DropDownButtonDifficultySettingsWidget({Key? key}) : super(key: key);
#override
State<DropDownButtonDifficultySettingsWidget> createState() => _DropDownButtonDifficultySettingsState();
}
class _DropDownButtonDifficultySettingsState extends State<DropDownButtonDifficultySettingsWidget> {
String dropdownValue = 'Medium';
#override
Widget build(BuildContext context) {
return Theme(
data: ThemeData(
splashColor: Colors.blue.withOpacity(0.4),),
child: DropdownButton<String>(
value: dropdownValue,
elevation: 8,
alignment: Alignment.centerRight,
iconDisabledColor: Colors.blue,
iconEnabledColor: Colors.blue,
underline: Container(
height: 0,
),
style: const TextStyle(color: Colors.blue, fontWeight: FontWeight.w500, ),
onChanged: (String? newValue) {
setState(() {
dropdownValue = newValue!;
});
},
items: <String>['Easy', 'Medium', 'Hard']
.map<DropdownMenuItem<String>>((String value) {
return DropdownMenuItem<String>(
value: value,
child: Text(value),
);
}).toList(),
),
);
}
}

Answer 1

You can include a callback method to get selected item from DropDownButtonDifficultySettingsWidget
class DropDownButtonDifficultySettingsWidget extends StatefulWidget {
final Function(String? selectedValue) callback;
const DropDownButtonDifficultySettingsWidget(
{Key? key, required this.callback})
: super(key: key);
#override
State<DropDownButtonDifficultySettingsWidget> createState() =>
_DropDownButtonDifficultySettingsState();
}
And on changed
onChanged: (String? newValue) {
setState(() {
dropdownValue = newValue!;
});
widget.callback(dropdownValue); //this
},
Now when ever you use DropDownButtonDifficultySettingsWidget you will get selected value on callback
DropDownButtonDifficultySettingsWidget(
callback: (selectedValue) {
print(selectedValue);
/// do the thing you like to have
},
),