Flutter Json序列化

Question

我目前正在构建一个应用程序，用户可以在其中将列表项作为收藏夹存储在他们的设备上。调试我的应用程序我运行出现以下错误：

Exception has occurred.
_CastError (type 'Null' is not a subtype of type 'Widget' in type cast)

这是我的代码：

LogEntry _$LogEntryFromJson(Map<String, dynamic> json) {
  return LogEntry(
      mechanismId: json['mechanismId'] as int?,
      timestamp: DateTime.parse(json['timestamp'] as String),
      navigation: json['navigation'] as Widget);
}

Map<String, dynamic> _$LogEntryToJson(LogEntry instance) => <String, dynamic>{
      'mechanismId': instance.mechanismId,
      'timestamp': instance.timestamp.toIso8601String(),
      'navigation:': instance.navigation,
    };

mechanismID为List项各自的ID，navigation代表详情页的路径

Answer 1

LogEntry _$LogEntryFromJson(Map<String, dynamic> json) {
  return LogEntry(
      mechanismId: json['mechanismId'] as int?,
      timestamp: DateTime.parse(json['timestamp'] as String),
      navigation: json['navigation'] as Widget?);
}

Flutter Json序列化

Flutter JsonSerialization

json

data-storage

jsonserializer

flutter