ktoJson<T> method
bean对象转json
User.ktoJson<User>((value) => user.toJson(value))
Implementation
String? ktoJson<T>(Map<String, dynamic> Function(T value) toJsonT) {
var file = this;
if (file == null) return null;
T t = file as T;
var jsonStr = toJsonT.call(t);
return jsonStr.ktoJson();
}