如何实现自定义JsonConverter .NET来为firestore序列化和反序列化对象

Question

我试图为具有嵌套对象的对象创建自定义json转换器，以作为正文发送到Firestore REST API：

public class Channel
{
    public string Name { get; private set; }
    public long OwnerId { get; private set; }
    public IEnumerable<Message> Messages { get; set; }
    public IEnumerable<User> Users { get; set; }
}

public class User
{
    public string UserId{ get; private set; }
    public string Pseudonym { get; private set; }
}

public class Message
{
    public long SenderUserId { get; private set; }
    public string text { get; private set; }
    public DateTime SentDate { get; private set; }
}

序列化时，json结构应如下所示：

{
        "OwnerId": {
            "stringValue": "id-1"
        },
        "Name": {
            "stringValue": "New Channel"
        },
        "Messages": {
            "arrayValue": {
                "values": [
                    {
                        "mapValue": {
                            "fields": {
                                "ConversationMessage": {
                                    "stringValue": "Hello kev"
                                },
                                "SenderUserId": {
                                    "stringValue": "id-1"
                                }
                            }
                        }
                    }
                ]
            }
        },
        "Users": {
            "arrayValue": {
                "values": [
                    {
                        "mapValue": {
                            "fields": {
                                "UserId": {
                                    "stringValue": "id-1"
                                },
                                "Pseudonym": {
                                    "stringValue": "raven"
                                }
                            }
                        }
                    },
                    {
                        "mapValue": {
                            "fields": {
                                "UserId": {
                                    "stringValue": "id-2"
                                },
                                "Pseudonym": {
                                    "stringValue": "kev"
                                }
                            }
                        }
                    }
                ]
            }
        }
    }

Firestore强制执行此结构，属性变为对象，类型为键，值为值（字符串变为stringValue，IEnumerable变为带有值的arrayValue，对象变为带字段的mapValue ...）

我应该为每个对象创建一个转换器，还是只为Channel对象创建一个转换器？任何答案或帮助将非常感谢，谢谢！