如何告訴 MongoDB C# 驅動程序存儲所有 Nullable<guids> 字符串格式？</guids>

Question

要將 Guid 序列化為字符串，我沒有問題，因為我使用的是以下代碼： https://stackoverflow.com/a/33258168/4148788

    var pack = new ConventionPack { new GuidAsStringRepresentationConvention () };
ConventionRegistry.Register("GuidAsString", pack, t => t == typeof (MyClass));

public class GuidAsStringRepresentationConvention : ConventionBase, IMemberMapConvention
    {
        public void Apply(BsonMemberMap memberMap)
        {
            if (memberMap.MemberType == typeof(Guid))
            {
                var serializer = memberMap.GetSerializer();
                var representationConfigurableSerializer = serializer as IRepresentationConfigurable;
                if (representationConfigurableSerializer != null)
                {
                    var reconfiguredSerializer = representationConfigurableSerializer.WithRepresentation(BsonType.String);
                    memberMap.SetSerializer(reconfiguredSerializer);
                }
            }
        }
    }

如果我嘗試為 Guid 做同樣的事情？ 它不起作用

            if (memberMap.MemberType == typeof(Guid?))
            {
                var serializer = memberMap.GetSerializer();
                var representationConfigurableSerializer = serializer as IRepresentationConfigurable;
                if (representationConfigurableSerializer != null)
                {
                    var reconfiguredSerializer = representationConfigurableSerializer.WithRepresentation(BsonType.String);
                    memberMap.SetSerializer(reconfiguredSerializer);
                }
            }

此行始終為 null：

                var representationConfigurableSerializer = serializer as IRepresentationConfigurable;

你如何處理可為空的Guids？

Answer 1

您需要重新配置當前的序列化程序還是可以直接替換它？ 替換它會更簡單。

可空類型的 BSON 序列化器被包裝在裝飾器序列化器類型 ( NullableSerializer<> ) 中，我們只需檢查MemberType是否為Nullable<Guid>並為您的場景設置正確的序列化器。

查看以下約定代碼：

public class GuidAsStringRepresentationConvention : ConventionBase, IMemberMapConvention
{
    public void Apply(BsonMemberMap memberMap)
    {
        if (memberMap.MemberType == typeof(Guid))
        {
            memberMap.SetSerializer(new GuidSerializer(BsonType.String));
        }
        else if (memberMap.MemberType == typeof(Guid?))
        {
            memberMap.SetSerializer(new NullableSerializer<Guid>(new GuidSerializer(BsonType.String)));
        }
    }
}

https://kevsoft.net/2020/06/25/storing-guids-as-strings-in-mongodb-with-csharp.html