如何在ListView Flutter中使用单选按钮

Question

我有一份品种清单[Chocolate, Strawberry, Vanilla]此列表可根据订购的菜单项(即[BBQ, Medium, Peri-Peri, Lemon & Herb](进行更改

我当前正确显示按钮但不起作用的代码是：

ListView.builder(
shrinkWrap: true,
itemCount: varietyList.length,
itemBuilder: ((context, index) {
return GFRadioListTile(
titleText: varietyList[index],
size: 25,
activeBorderColor: Colors.black,
focusColor: Colors.black,
type: GFRadioType.basic,
value: 0,
groupValue: 1,
onChanged: (value) {},
inactiveIcon: null,
);
})),

其中``int number=20''。这个变量和金额是基于另一篇帖子，代码如下：

ListView.builder(
shrinkWrap: true,
itemCount: varietyList.length,
itemBuilder: ((context, index) {
return RadioListTile(
value: index,
groupValue: number,
onChanged: (ind) => setState(() => number = ind),
);
})),

但上面写着"；"Object？"类型的值无法将其分配给"int"类型的变量">

如何使收音机按钮正常工作？

Answer 1

修复"对象不能是int"；问题是我必须为ind对象添加as int。

GFRadioListTile(
padding: const EdgeInsets.all(13),
color: Colors.white,
radioColor: Color.fromARGB(255, 138, 5, 5),
title: Text(
varietyList[index],
style: const TextStyle(
fontSize: 25, color: Colors.black),
),
size: 28,
activeBorderColor: Colors.black,
focusColor: Colors.black,
type: GFRadioType.basic,
value: index,
groupValue: number,
onChanged: (ind) =>
setState(() => number = ind! as int),
inactiveIcon: null,
);