小编laa*_*IGL的帖子

我正在尝试将对象“Week”转换为 json。

https://flutter.dev/docs/development/data-and-backend/json这是我使用的源

class Week{
  DateTime _startDate;
  DateTime _endDate;
  List<Goal> _goalList;
  String _improvement;

  Week(this._startDate, this._endDate){
    this._goalList = List<Goal>();
    this._improvement = "";
  }

  Week.fromJson(Map<String, dynamic> json)
    : _startDate =  json['startDate'],
      _endDate = json['endDate'],
      _goalList = json['goalList'],
      _improvement = json['improvement'];

  Map<String, dynamic> toJson() => 
  {
    'startDate': _startDate,
    'endDate': _endDate,
    'goalList': _goalList,
    'improvement': _improvement,
  };
}

我用过这个：

DateTime startDate = currentDate.subtract(new Duration(days:(weekday-1)));
DateTime endDate = currentDate.add(new Duration(days:(7-weekday)));

Week week = new Week(startDate, endDate);
var json = jsonEncode(week);

但问题是我得到了这个结果：

Unhandled Exception: Converting object …

为了在改变屏幕时有动画，我正在使用page_transition: ^1.1.5

这是一个例子：

Navigator.push(context, PageTransition(type: PageTransitionType.rightToLeft, child: HandymanDocumentsOverview(), duration: Duration(milliseconds: 150)));\n

昨天我安装firebase_core: ^0.5.0并更新了所有其他 Firebase 依赖项。不知何故，感觉动画速度Navigator.pop(context);比以前慢了很多，甚至与第一个动画速度不匹配。\n有人知道如何解决这个问题吗？

这里编辑的是我的flutter doctor -v

[\xe2\x9c\x93] Flutter (Channel stable, 1.22.0, on Mac OS X 10.15.4 19E287, locale de-DE)\n    \xe2\x80\xa2 Flutter version 1.22.0 at /Users/bastianmeyer/flutter\n    \xe2\x80\xa2 Framework revision d408d302e2 (3 days ago), 2020-09-29 11:49:17 -0700\n    \xe2\x80\xa2 Engine revision 5babba6c4d\n    \xe2\x80\xa2 Dart version 2.10.0\n\n \n[\xe2\x9c\x93] Android toolchain - develop for Android devices (Android SDK version 29.0.3)\n    \xe2\x80\xa2 Android …