Question

如何从ChoiceChip小部件中检索数据，并在按下按钮时将其传递给另一个小部件。

这是我的ChoiceChip

class ChoiceChipWidget extends StatefulWidget {
  final List<String> reportList;

  ChoiceChipWidget(this.reportList);

  @override
  _ChoiceChipWidgetState createState() => new _ChoiceChipWidgetState();
}

class _ChoiceChipWidgetState extends State<ChoiceChipWidget> {
  String selectedChoice = "";

  _buildChoiceList() {
    List<Widget> choices = List();
    widget.reportList.forEach((item) {
      choices.add(Container(
        child: ChoiceChip(
          label: Text(item),
          selected: selectedChoice == item,
          onSelected: (selected) {
            setState(() {
              selectedChoice = item;
            });
          },
        ),
      ));
    });
    return choices;
  }

  @override
  Widget build(BuildContext context) {
    return Wrap(
      children: _buildChoiceList(),
    );
  }
}

我想在按下按钮时在此小部件中传递它。

class AddCashForm extends StatefulWidget {
  @override
  _AddCashFormState createState() => _AddCashFormState();
}

class _AddCashFormState extends State<AddCashForm> {
  List<String> chipList = [
    "weekly",
    "bi-weekly",
    "monthly",
    "once",
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: new COHAppBar().getAppBar(),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          Row(
            children: <Widget>[
              ChoiceChipWidget(chipList),
            ],
          ),
          RaisedButton(
            child: Text("Update Cash Flow"),
            onPressed: () {
              setState(() {});
            },
          ),

          //Text('${widget.selectedChoice ?? "File is empty"}'), Data goes here
        ],
      ),
    );
  }
}

... 我是否需要添加一个构造函数，以便在按下botton时可以传递数据？如何在这样的小部件之间传递数据

Answer 1

您可以在按下事件中的RaisedButton中添加以下行：-

final Route route = MaterialPageRoute(builder: (context) => ChoiceChipWidget(true));
Navigator.push(mContext, route);

Answer 2

您可以使用这样的回调函数：

class ChoiceChipWidget extends StatefulWidget {
  final List<String> reportList;
  final Function(String item) onItemSelected;

  ChoiceChipWidget(this.reportList, this.onItemSelected);

  @override
  _ChoiceChipWidgetState createState() => new _ChoiceChipWidgetState();
}

选择该项目后，按如下所示调用函数：

onSelected: (selected) {
  setState(() {
    selectedChoice = item;
    widget.onChoiceSelected(item);
  });
}

然后，在创建窗口小部件时，您可以执行以下操作：

ChoiceChipWidget(chipList, (item) {
  print('Item selected: $item');
})

在小部件之间传递数据

2 个答案: