dropdownmenuitem flutter example onChanged

Example: how to create drop down list in flutter

new DropdownButton<String>(
  items: <String>['A', 'B', 'C', 'D'].map((String value) {
    return new DropdownMenuItem<String>(
      value: value,
      child: new Text(value),
    );
  }).toList(),
  onChanged: (_) {},
)