c# - Entity Framework detach entity not working -

i'm implementing generic auditing in class. want detach entity context , serialize , save json string of serialized entity in db part of audit logic. because objects have references serializing fails reason. implemented logic set null class.propertytype.isgenerictype , works fine. after creating audit log , call context.savechanges, saves entity unset properties changes did detach context.

anyway can make code work?

note: newitem still being tracked context...

context.entry<t>( newitem ).state = system.data.entity.entitystate.detached; context.savechanges();  var props = newitem.gettype().getproperties().where( p => p.propertytype.isgenerictype );  foreach ( var item in props ) {    item.setvalue( newitem, null ); }  auditlog log = new auditlog() {    createdon = datetime.now,    modifiedon = datetime.now,    type = ( int32 ) activity,    actiontable = newitem.gettype().name,    userid = ( ( currentuser != null ) ? currentuser.id : 0 ),    afterimage = new javascriptserializer().serialize( newitem ),    modifiedby = ( ( currentuser != null ) ? currentuser.email : "system" ),    comments = string.format( "created new {0}", newitem.gettype().name ),    beforeimage = ( olditem != null ) ? new javascriptserializer().serialize( olditem ) : string.empty,    objectid = ( int32 ) newitem.gettype().getproperties().firstordefault( x => x.name == "id" ).getvalue( newitem ),    parameters = new javascriptserializer().serialize( httpcontext.current.request.requestcontext.routedata.values ) };  context.logs.add( log ); context.savechanges(); // when execute this, changes in foreach loop saved newitem 

thanks in advance.