小编Mar*_*s.L的帖子

我试图从对话框返回一个布尔值，但我不明白为什么该值没有根据需要返回。我尝试返回作为未来值，并在弹出对话框后将值与上下文一起返回。

final bool delete = await _showDialog();
print(delete);

Future<bool> _showDialog() {
bool result;

showDialog(
  context: context,
  builder: (BuildContext context) {
    return AlertDialog(
      title: Text('Delete Appointment'),
      content: Text(
        'Are you sure? \nThis action cannot undo.',
        style: TextStyle(
          color: Colors.red,
          fontSize: 20
        ),
      ),
      actions: <Widget>[
        FlatButton(
          color: Colors.blue,
          child: Text(
            'CANCEL',
            style: TextStyle(
              color: Colors.white,
              fontSize: 20
            ),
          ),
          onPressed: () {
            setState(() => result = false);
            //print(result);
            Navigator.pop(context, result);
            return Future.value(result);
          },
        ),
        SizedBox(
          width: 50,
        ),
        FlatButton(
          color: Colors.red, …