在多个下拉菜单中，如果已在 Flutter 中选择，如何禁用选项？

Question

I have 4 different dropdown fields with 5 options and I want to disable/remove an option from other fields if the option is already selected.

Screenshot: Screenshot 1 Screenshot 2

DropDown Menu Code:

 String opemo1, opemo2, opemo3, opemo4; List<String> emoji = [ "❤️", "", "✌️", "", "", ];

 DropdownButtonFormField( validator: (value) => value == null? 'required': null, hint: Text('❤️'), value: opemo1, icon: Icon(Icons.arrow_drop_down), iconSize: 36, isExpanded: true, style: TextType.regularDarkText, onChanged: (newValue) { setState(() { opemo1 = newValue; pollDataController.setop1Emoji(newValue); }); }, items: emoji.map((opemo1) { return DropdownMenuItem( value: opemo1, child: Text(opemo1), ); }).toList(), ),

Answer 1

To manage it you need to remove the selected emoji from List<String> emoji .

onChanged: (newValue) {
    setState(() {
        emoji.removeWhere((element) => element == newValue); /// This removed selected emoji.
        opemo1 = newValue;
        pollDataController.setop1Emoji(newValue);
    });
},

You can replace your onChanged with this snippet.