c#-将自定义对象添加到JObject时出错

public class RequestEntity
{
    public int Category { get; set; }
    public List<string> Types { get; set; }
    public List<Parameters> parameters { get; set; }
}

public class Parameters
{
    public string Name { get; set; }
    public string Type { get; set; }
    public bool IsRecent { get; set; }
}

将值设置为：

List<RequestEntity> request = new List<RequestEntity>();

现在,我需要创建一个具有2个属性的JObject.

JObject requestObject = new JObject();
JProperty property1 = new JProperty("Details", request);
JProperty property2 = new JProperty("SpanInDays", 10);
requestObject.Add(property1);
requestObject.Add(property2);

行JProperty property1 = new JProperty(“ Details”,request);给我以下错误.

无法确定类型DAL.Entity.RequestEntity的JSON对象类型.

JProperty property1 = new JProperty("Details", JToken.FromObject(request));