dart - Flutter 复选框类 : When I tick a card, 所有其他的也都被选中

Question

  bool selected = false;

   new Card(
          shape: selected
              ? new RoundedRectangleBorder(
              side: new BorderSide(color: Colors.blue, width: 2.0),
              borderRadius: BorderRadius.circular(4.0))
              : new RoundedRectangleBorder(
              side: new BorderSide(color: Colors.white, width: 2.0),
              borderRadius: BorderRadius.circular(4.0)),

          child: new Row(


              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: <Widget>[



            new Padding(
              padding: new EdgeInsets.all(8.0),
              child: new Text("${ticketGroups[i]['ticket_name']}",
                  style: const TextStyle(
                      fontSize: 15.0, fontFamily: 'Poppins')),
            ),
            new Padding(
              padding: new EdgeInsets.all(8.0),
              child: new Text(ticketGroups[i]["used"].toString(),
                  style: const TextStyle(
                      fontSize: 15.0, fontFamily: 'Poppins')),
            ),

            new Checkbox(
                value: selected,
                onChanged: (value) {
                  setState(() {
                    selected = !selected;
                  });

                })

我希望只能勾选一张卡片，但是只要我勾选任何一张，所有卡片都会被勾选。卡片也是动态创建的，会不会是这个问题导致的？

Answer 1

正如 Günter 在他的评论中所说，您需要为每个卡片/列表项创建一个索引。到目前为止，我看到的最佳选择是将 ListView 与 itemBuilder 一起使用，如下所示:

return new ListView.builder(
  itemBuilder: (context, index) => new Card(
      shape: selected[index]
          ? new RoundedRectangleBorder(
          side: new BorderSide(color: Colors.blue, width: 2.0),
          borderRadius: BorderRadius.circular(4.0))
          : new RoundedRectangleBorder(
          side: new BorderSide(color: Colors.white, width: 2.0),
          borderRadius: BorderRadius.circular(4.0)),
          ...
  itemCount: selected.length, // Tell itemBuilder how many items the list has
  ... // Rest of your code...
);