C# newtonsoft序列化将long类型转化为字符串

/// 

/// 转化为json的时候long类型转为string
/// 
public class LongJsonConverter: JsonConverter
{
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        try
        {
            return reader.Value.ObjToLong();
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    public override bool CanConvert(Type objectType)
    {
        return true;
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        if (value == null)
        {
            writer.WriteNull();
            return;
        }
        string sValue = value.ToString();
        writer.WriteValue(sValue);
    }
}

全局使用

services.AddControllers(options =>
{
	//添加过滤器
    //options.Filters.Add(new AdminIpFilter(Configuration));
})
 .AddNewtonsoftJson(options =>
 {
     options.SerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
     options.SerializerSettings.Converters.Add(new Common.NewtonsoftJsonConvert.LongNullConverter());
     //修改属性名称的序列化方式，首字母小写
     options.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
     //修改时间的序列化方式
     options.SerializerSettings.Converters.Add(new IsoDateTimeConverter() { DateTimeFormat = "yyyy-MM-dd HH:mm:ss" });
     //看这里
     options.SerializerSettings.Converters.Add(new LongJsonConverter());
 });

针对某个属性使用

[JsonConverter(typeof(LongJsonConverter))]
public long? Id { get; set; }