我猜你想返回该类作为JSON。

I guess you want to return that class as JSON.

你可以做的仍然是使用的StringContent 的构造函数，但是传递一个JSON序列化的字符串。你可以使用Newtonsoft.Json作为系列化。

What you could do is still use the StringContent constructor, but pass in a JSON serialized string. You could use Newtonsoft.Json as serialized.

throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.InternalServerError)
{
    Content = new StringContent(JsonConvert.SerializeObject(yourObject))
});