Flutter 复选框在 AlertDialog 中不起作用

Question

我正在 AlertDialog 中做一个复选框。我希望用户在上传之前勾选复选框。我的问题是，如果我将变量设置为 false ，复选框将不会更改为 true 或更改回 false。这是我的代码：

bool _isChecked = false;

List<String> _texts = [
 "I have confirm the data is correct",
 "I have agreed to terms and conditions.",
];

showConfirmationDialog(BuildContext context){
      AlertDialog alert=AlertDialog(
        title: Text('Confirmation'),
        content: 
        ListView(
        padding: EdgeInsets.all(8.0),
        children: _texts.map((text) => CheckboxListTile(
          title: Text(text),
            value: _isChecked,
            onChanged: (val) {
            setState(() {
            _isChecked = val;           
              });
            },
          )).toList(),
        ),
        actions: <Widget>[
          SizedBox(
            width: 300, 
            child:RaisedButton(
              color: Colors.blue,
              onPressed: () => upload(context), 
              child:Text('Upload'),
            )
          )
        ],
      );
      showDialog(barrierDismissible: false,
        context:context,
        builder:(BuildContext context){
          return alert;
        },
      );
  }

谁能帮我？

Answer 1

您需要有状态的小部件，因为 showDialog 无法更改状态。

下面的代码可以帮助您了解更多。

class DeleteWidget extends StatefulWidget {
  @override
  _DeleteWidgetState createState() => _DeleteWidgetState();
}

class _DeleteWidgetState extends State<DeleteWidget> {
  var currentSection;
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: RaisedButton(
            onPressed: () {
              showConfirmationDialog(context);
            },
            child: Text("data"),
          ),
        ),
      ),
    );
  }

  showConfirmationDialog(BuildContext context) {
    showDialog(
      barrierDismissible: false,
      context: context,
      builder: (BuildContext context) {
        return CustomDialog();
      },
    );
  }
}

class CustomDialog extends StatefulWidget {
  @override
  _CustomDialogState createState() => _CustomDialogState();
}

class _CustomDialogState extends State<CustomDialog> {
  List<bool> _isChecked = [false, false];
  bool canUpload = false;
  List<String> _texts = [
    "I have confirm the data is correct",
    "I have agreed to terms and conditions.",
  ];
  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Text('Confirmation'),
      content: Container(
        width: MediaQuery.of(context).size.width,
        height: MediaQuery.of(context).size.height,
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Expanded(
              child: ListView(
                  shrinkWrap: true,
                  padding: EdgeInsets.all(8.0),
                  children: [
                    ListView.builder(
                      shrinkWrap: true,
                      itemCount: _texts.length,
                      itemBuilder: (_, index) {
                        return CheckboxListTile(
                          title: Text(_texts[index]),
                          value: _isChecked[index],
                          onChanged: (val) {
                            setState(() {
                              _isChecked[index] = val;
                              canUpload = true;
                              for (var item in _isChecked) {
                                if (item == false) {
                                  canUpload = false;
                                }
                              }
                            });
                          },
                        );
                      },
                    ),
                  ]),
            ),
          ],
        ),
      ),
      actions: <Widget>[
        SizedBox(
            width: 300,
            child: RaisedButton(
              color: Colors.blue,
              onPressed: canUpload
                  ? () {
                      print("upload");
                    }
                  : null,
              child: Text('Upload'),
            ))
      ],
    );
  }
}