[英]In Flutter, how to make a user selected dropdown menu option leads to a specific route?
[英]In multiple dropdown menu, how to disable an option if already selected in Flutter?
我有 4 個不同的下拉字段和 5 個選項,如果已選擇該選項,我想從其他字段中禁用/刪除該選項。
下拉菜單代碼:
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(), ),
要管理它,您需要從List<String> emoji
中刪除選定的表情符號。
onChanged: (newValue) {
setState(() {
emoji.removeWhere((element) => element == newValue); /// This removed selected emoji.
opemo1 = newValue;
pollDataController.setop1Emoji(newValue);
});
},
您可以使用此代碼段替換您的onChanged
。
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