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