flutter dropdownbutton
String dropdownValue = 'One';
DropdownButton<String>(
value: dropdownValue,
onChanged: (String? newValue) {
setState(() {
dropdownValue = newValue!;
});
},
items: <String>['One', 'Two', 'Free', 'Four']
.map<DropdownMenuItem<String>>((String value) {
return DropdownMenuItem<String>(
value: value,
child: Text(value),
);
}).toList(),
),