C#实体集合转Dictionary

[Tanrili]

类的结构是
public class FastEnrollMemberRequest:
｛
public string SourceNo { get; set; }
public string ContactLanguage { get; set; }
public UniEnrollMemberFlight[] Flightitem { get; set; }
public UniEnrollMemberAssist[] Assistitem { get; set; }

｝
public class UniEnrollMemberFlight
{

public string Carrier{ get; set; }
｝

public class UniEnrollMemberAssist
{

public string StewardCode { get; set; }
}
怎么通过Dictionary 转换成Json格式，格式如下
{"accessToken"：“123123” ，
"parameters"：
{
SourceNo =“1”；
ContactLanguage =2；
UniEnrollMemberFlight：
｛
Carrier=0；
}
UniEnrollMemberAssist::
{
StewardCode =2
}
｝
｝

[Tanrili]

var dictionary = new Dictionary<string, object> { {"accessToken", request.AccessToken}, { "parameters", new FastEnrollMemberRequest { SourceNo=request.SourceNo, ContactLanguage=request.ContactLanguage } } }; 只知道这样写，不知道怎么把UniEnrollMemberFlight 和 UniEnrollMemberAssist 里的值加进字典

[ajianchina]

new FastEnrollMemberRequest
                    {
                       SourceNo=request.SourceNo,
                       ContactLanguage=request.ContactLanguage ,
                       Flightitem = new UniEnrollMemberFlight[]{new UniEnrollMemberFlight(){Carrier=request.Flightitem}},
                       Assistitem = new UniEnrollMemberAssist[]{new UniEnrollMemberAssist(){StewardCode=request.Assistitem}}
                    }