c# - asp.net core: Preserve ForeignKey Relation in JsonResult -

when send object database (entityframework) using jsonresult without foreign key result need. if object contains foreignkey relation relation not in resulting json:

what get:

{     "agentid":"9990447f-6703-11e7-9c8b-94de80ab7fee",     ...     "configurationid": 22,     "configuration": null } 

what need:

{     "agentid":"9990447f-6703-11e7-9c8b-94de80ab7fee",     ...     "configurationid": 22,     "configuration": {         "id": 0,         ...     } } 

what can preserve foreign key relation in json?

i tried set following:

services.addmvc().addjsonoptions(options => options.serializersettings.preservereferenceshandling = preservereferenceshandling.all); 

ef context:

public class agent {     [key]     public guid agentid { get; set; }     ...     public int? configurationid { get; set; }     [foreignkey("configurationid")]     public configuration configuration { get; set; } }  public class configuration {     public int id { get; set; }     ...     public icollection<agent> agents { get; set; } } 

controller:

[httpget] public jsonresult index() {     var agentlist = _databasecontext.agents;     return new jsonresult(agentlist); } 

you can load related data

[httpget] public jsonresult index() {     var agentlist = _databasecontext.agents                                     .include(agent=> agent.configuration)                                     .tolist();;     return new jsonresult(agentlist); }