c# - Using DTO in Azure Mobile Service .NET throws target invocation exception -

i use azure mobile services .net backend , know have use entity framework classes map database creation/migration. need use dtos serialize properties want, computed properties etc. i'm following field engineer example. automapper gave me pain although did supposed to.

i have checked couple of others blog , site, use automapper, others not, example this one. feel more comfortable not using automapper , create dtos on fly select() doing before when implementing web api.

i reverted tablecontroller class post, use entitydomainmanager , left getallposts method following.

public class postcontroller : tablecontroller<post> {     private mobileservicecontext _context;      protected override void initialize(httpcontrollercontext controllercontext)     {         base.initialize(controllercontext);         _context = new mobileservicecontext();         domainmanager = new entitydomainmanager<post>(_context, request, services);     }      //[expandproperty("user")]     // tables/post     public iqueryable<postdto> getallpost()     {         return query().include("user").select(x => new postdto());     } } 

i following error.

{"message":"an error has occurred.","exceptionmessage":"exception has been thrown target of invocation.","exceptiontype":"system.reflection.targetinvocationexception","stacktrace":"   @ system.runtimemethodhandle.invokemethod(object target, object[] arguments, signature sig, boolean constructor)\r\n   @ system.reflection.runtimemethodinfo.unsafeinvokeinternal(object obj, object[] parameters, object[] arguments)\r\n   @ system.reflection.runtimemethodinfo.invoke(object obj, bindingflags invokeattr, binder binder, object[] parameters, cultureinfo culture)\r\n   @ system.reflection.methodbase.invoke(object obj, object[] parameters)\r\n   @ system.web.http.odata.query.odataqueryoptions.limitresults(iqueryable queryable, int32 limit, boolean& resultslimited)\r\n   @ system.web.http.odata.query.odataqueryoptions.applyto(iqueryable query, odataquerysettings querysettings)\r\n   @ system.web.http.odata.enablequeryattribute.applyquery(iqueryable queryable, odataqueryoptions queryoptions)\r\n   @ system.web.http.odata.enablequeryattribute.executequery(object response, httprequestmessage request, httpactiondescriptor actiondescriptor)\r\n   @ system.web.http.odata.enablequeryattribute.onactionexecuted(httpactionexecutedcontext actionexecutedcontext)\r\n   @ system.web.http.filters.actionfilterattribute.onactionexecutedasync(httpactionexecutedcontext actionexecutedcontext, cancellationtoken cancellationtoken)\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.compilerservices.taskawaiter.throwfornonsuccess(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.handlenonsuccessanddebuggernotification(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.getresult()\r\n   @ system.web.http.filters.actionfilterattribute.<callonactionexecutedasync>d__5.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.compilerservices.taskawaiter.throwfornonsuccess(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.handlenonsuccessanddebuggernotification(task task)\r\n   @ system.runtime.compilerservices.taskawaiter`1.getresult()\r\n   @ system.web.http.filters.actionfilterattribute.<executeactionfilterasynccore>d__0.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.compilerservices.taskawaiter.throwfornonsuccess(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.handlenonsuccessanddebuggernotification(task task)\r\n   @ system.runtime.compilerservices.taskawaiter`1.getresult()\r\n   @ system.web.http.filters.actionfilterattribute.<callonactionexecutedasync>d__5.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.exceptionservices.exceptiondispatchinfo.throw()\r\n   @ system.web.http.filters.actionfilterattribute.<callonactionexecutedasync>d__5.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.compilerservices.taskawaiter.throwfornonsuccess(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.handlenonsuccessanddebuggernotification(task task)\r\n   @ system.runtime.compilerservices.taskawaiter`1.getresult()\r\n   @ system.web.http.filters.actionfilterattribute.<executeactionfilterasynccore>d__0.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.compilerservices.taskawaiter.throwfornonsuccess(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.handlenonsuccessanddebuggernotification(task task)\r\n   @ system.runtime.compilerservices.taskawaiter`1.getresult()\r\n   @ system.web.http.controllers.actionfilterresult.<executeasync>d__2.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.compilerservices.taskawaiter.throwfornonsuccess(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.handlenonsuccessanddebuggernotification(task task)\r\n   @ system.runtime.compilerservices.taskawaiter`1.getresult()\r\n   @ system.web.http.filters.authorizationfilterattribute.<executeauthorizationfilterasynccore>d__2.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.compilerservices.taskawaiter.throwfornonsuccess(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.handlenonsuccessanddebuggernotification(task task)\r\n   @ system.runtime.compilerservices.taskawaiter`1.getresult()\r\n   @ system.web.http.controllers.authenticationfilterresult.<executeasync>d__0.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.compilerservices.taskawaiter.throwfornonsuccess(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.handlenonsuccessanddebuggernotification(task task)\r\n   @ system.runtime.compilerservices.taskawaiter`1.getresult()\r\n   @ system.web.http.controllers.exceptionfilterresult.<executeasync>d__0.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.exceptionservices.exceptiondispatchinfo.throw()\r\n   @ system.web.http.controllers.exceptionfilterresult.<executeasync>d__0.movenext()\r\n--- end of stack trace previous location exception thrown ---\r\n   @ system.runtime.compilerservices.taskawaiter.throwfornonsuccess(task task)\r\n   @ system.runtime.compilerservices.taskawaiter.handlenonsuccessanddebuggernotification(task task)\r\n   @ system.runtime.compilerservices.taskawaiter`1.getresult()\r\n   @ system.web.http.dispatcher.httpcontrollerdispatcher.<sendasync>d__1.movenext()","innerexception":{"message":"an error has occurred.","exceptionmessage":"the specified type member 'dateposted' not supported in linq entities. initializers, entity members, , entity navigation properties supported.","exceptiontype":"system.notsupportedexception","stacktrace":"   @ system.data.entity.core.objects.elinq.expressionconverter.memberaccesstranslator.typedtranslate(expressionconverter parent, memberexpression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.typedtranslator`1.translate(expressionconverter parent, expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translateexpression(expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translatelambda(lambdaexpression lambda, dbexpression input)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translatelambda(lambdaexpression lambda, dbexpression input, dbexpressionbinding& binding)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.onelambdatranslator.translate(expressionconverter parent, methodcallexpression call, dbexpression& source, dbexpressionbinding& sourcebinding, dbexpression& lambda)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.onelambdatranslator.translate(expressionconverter parent, methodcallexpression call)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.sequencemethodtranslator.translate(expressionconverter parent, methodcallexpression call, sequencemethod sequencemethod)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.typedtranslate(expressionconverter parent, methodcallexpression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.typedtranslator`1.translate(expressionconverter parent, expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translateexpression(expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translateset(expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.thenbytranslatorbase.translate(expressionconverter parent, methodcallexpression call)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.sequencemethodtranslator.translate(expressionconverter parent, methodcallexpression call, sequencemethod sequencemethod)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.typedtranslate(expressionconverter parent, methodcallexpression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.typedtranslator`1.translate(expressionconverter parent, expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translateexpression(expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translateset(expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.thenbytranslatorbase.translate(expressionconverter parent, methodcallexpression call)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.sequencemethodtranslator.translate(expressionconverter parent, methodcallexpression call, sequencemethod sequencemethod)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.typedtranslate(expressionconverter parent, methodcallexpression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.typedtranslator`1.translate(expressionconverter parent, expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translateexpression(expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translateset(expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.unarysequencemethodtranslator.translate(expressionconverter parent, methodcallexpression call)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.sequencemethodtranslator.translate(expressionconverter parent, methodcallexpression call, sequencemethod sequencemethod)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.methodcalltranslator.typedtranslate(expressionconverter parent, methodcallexpression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.typedtranslator`1.translate(expressionconverter parent, expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.translateexpression(expression linq)\r\n   @ system.data.entity.core.objects.elinq.expressionconverter.convert()\r\n   @ system.data.entity.core.objects.elinq.elinqquerystate.getexecutionplan(nullable`1 formergeoption)\r\n   @ system.data.entity.core.objects.objectquery`1.<>c__displayclass7.<getresults>b__6()\r\n   @ system.data.entity.core.objects.objectcontext.executeintransaction[t](func`1 func, idbexecutionstrategy executionstrategy, boolean startlocaltransaction, boolean releaseconnectiononsuccess)\r\n   @ system.data.entity.core.objects.objectquery`1.<>c__displayclass7.<getresults>b__5()\r\n   @ system.data.entity.sqlserver.defaultsqlexecutionstrategy.execute[tresult](func`1 operation)\r\n   @ system.data.entity.core.objects.objectquery`1.getresults(nullable`1 formergeoption)\r\n   @ system.data.entity.core.objects.objectquery`1.<system.collections.generic.ienumerable<t>.getenumerator>b__0()\r\n   @ system.data.entity.internal.lazyenumerator`1.movenext()\r\n   @ system.collections.generic.list`1..ctor(ienumerable`1 collection)\r\n   @ system.web.http.odata.query.truncatedcollection`1..ctor(iqueryable`1 source, int32 pagesize)\r\n   @ system.web.http.odata.query.odataqueryoptions.limitresults[t](iqueryable`1 queryable, int32 limit, boolean& resultslimited)"}} 

if convert entity framework class works. notice don't fill property, testing purposes.

i test locally iis express.

data objects , models.

    public class post : entitydata     {         public datetimeoffset dateposted { get; set; }         public string statustext { get; set; }         public posttype typeofpost { get; set; }          [foreignkey("id")]         public virtual user user { get; set; }          [foreignkey("id")]         public virtual icollection<postphotourl> photourls { get; set; }     }      public class postdto     {         public postdto()         {             photourls = new hashset<postphotourldto>();             }          public datetimeoffset dateposted { get; set; }         public string statustext { get; set; }         public int typeofpost { get; set; }          public userdto user { get; set; }         public icollection<postphotourldto> photourls { get; set; }     } 

searching internet couldn't find other more clear tutorial how use azure mobile services , dtos, though shouldn't introduce such difficulty. if have resources welcome.

i should mention if don't following test website raises error when trying test endpoints.

config.formatters.jsonformatter.serializersettings.referenceloophandling = referenceloophandling.ignore; 

the exception snapshot:

i don't need have dtos project, if don't resolve don't understand right come , hunt me in long run of service.

i'm not sure think problem may line of code

return query().include("user").select(x => new postdto()); 

if youre not using automapper need manually parse properties in select statement this

return query().include("user")               .select(x => new postdto()                {                    dateposted = x.dateposted,                    statustext = x.statustext,                    typeofpost = x.typeofpost,                    user = new userdto                           {                               //your propertoes here                               //eg id = x.user.id etc                            }                  );