Sometimes adding a WCF Service Reference generates an empty reference cs

Question

Sometimes adding a WCF Service Reference generates an empty reference cs and I cannot reference the service anywhere in the project   Has anyone encountered this

User · Answer

If you recently added a collection to your project when this started to occur, the problem may be caused by two collections which have the same CollectionDataContract attribute:

[CollectionDataContract(Name="AItems", ItemName="A")]
public class CollectionA : List<A> { }

[CollectionDataContract(Name="AItems", ItemName="A")]  // Wrong
public class CollectionB : List<B> { }

I fixed the error by sweeping through my project and ensuring that every Name and ItemName attribute was unique:

[CollectionDataContract(Name="AItems", ItemName="A")]
public class CollectionA : List<A> { }

[CollectionDataContract(Name="BItems", ItemName="B")]  // Corrected
public class CollectionB : List<B> { }

Then I refreshed the service reference and everything worked again.

User · Answer

The following is not listed here  and it was the solution I adopted  SvcUtils was useful in seeing the error message  However  the error I got was wrapper type message cannot be projected as a data contract type since it has multiple namespaces  Meaning  I followed this lead  and learned about wsdl exe via this post    In my case  simply running wsdl  my-asmx-service-address  generated a problem-free  cs file  which I included in my project and instanced to use the service

User · Answer

Follow these steps     Remove Service Reference Close Visual Studio Delete  Bin and  Obj folders  Open Visual Studio  Add the Service Reference  You re Welcome      It seems that some references are left in these folders when adding the service  causing errors during the auto-generation of code

User · Answer

In my case I had a solution with VB Web Forms project that referenced a C  UserControl   Both the VB project and the CS project had a Service Reference to the same service   The reference appeared under Service References in the VB project and under the Connected Services grouping in the CS  framework  project   In order to update the service reference  ie  get the Reference vb file to not be empty  in the VB web forms project  I needed to REMOVE THE CS PROJECT  then update the VB Service Reference  then add the CS project back into the solution

User · Answer

When this happens  look in the Errors window and the Output window to see if there are any error messages  If that doesn t help  try running svcutil exe manually  and see if there are any error messages

User · Answer

My issue was that I left the  mex  onto the end of my web service link   Instead of  http   yeagertech com yeagerte YeagerTechWcfService YeagerTechWcfService svc mex   Use  http   yeagertech com yeagerte YeagerTechWcfService YeagerTechWcfService svc

User · Answer

I have found this to occur commonly whenever I add a reference  remove it  and then re-add a service with the same name   The type conflicts appear to be caused by the old files remaining somewhere that Visual Studio can still see   All I need to do to fix it  is a clean before adding the new reference    Remove the service reference having issues  Click on the project name in the Solution Explorer to highlight the project  Right-click on the project reference  Near the top of the context list  click the Clean item  Add your service reference as you normally would    Hope this helps

User · Answer

When attempting to troubleshoot this problem with svcutil  I received the error referred to in dblood s answer   referenced type cannot be used since it does not match imported DataContract     In my case the underlying cause seemed to be an enum type that had the DataContract attribute  but whose members were not marked with the EnumMember attribute  The problem class svcutil pointed at had a property with that enum type   This would fit better as a comment to dblood s answer  but not enough rep for that

User · Answer

I also had the issue of broken service references when working with project references on both sides  the service project and the project having a reference to the service    If the the  dll of the referenced project for example is called  Contoso Development Common   but the projects name is simply shortened to  Common   also project references to this project are named just  Common   The service however expects a reference to  Contoso Development Common  for resolving classes  if this option is activated in the service reference options    So with explorer I opened the folder of the project which is referencing the service and the  Common -project  There I editet the VS project file   csproj  with notepad   Search for the name of the refernced project  which is  Common csproj  in this example  and you will quickly find the configuration entry representing the project reference   I changed    lt ProjectReference Include     Common Common csproj  gt      lt Project gt  C90AAD45-6857-4F83-BD1D-4772ED50D44C  lt  Project gt      lt Name gt Common lt  Name gt   lt  ProjectReference gt   to   lt ProjectReference Include     Common Common csproj  gt      lt Project gt  C90AAD45-6857-4F83-BD1D-4772ED50D44C  lt  Project gt      lt Name gt Contoso Development Common lt  Name gt   lt  ProjectReference gt   The important thing is to change the name of the reference to the name of the dll the referenced project has as output   Then switch back to VS  There you will be asked to reload the project since it has been modified outside of VS  Click the reload button   After doing so adding und updating the service reference worked just as expected   Hope this also helps someone else   Regards MH

User · Answer

Generally I find that it s a code-gen issue and most of the time it s because I ve got a type name conflict it couldn t resolve   If you right-click on your service reference and click configure and uncheck  Reuse Types in Referenced Assemblies  it ll likely resolve the issue   If you were using some aspect of this feature  you might need to make sure your names are cleaned up

User · Answer

As the accepted answer points out  a type reference issue when reusing types is probably the culprit  I found when you cannot easily determine the issue then using svcutil exe command line will help you reveal the underlying problem  as John Saunders points out    As an enhancement here is a quick example of using svcutil   svcutil  t code https   secure myserver com services MyService svc  d test  r  C  MyCode MyAssembly bin debug MyAssembly dll    Where     t code generates the code from given url  d  to specify the directory for the output  r  to specify a reference assembly   Full svcutil command line reference here  http   msdn microsoft com en-us library aa347733 aspx  Once you run svcutil  you should see the exception being thrown by the import   You may receive this type of message about one of your types   referenced type cannot be used since it does not match imported DataContract    This could simply be as specified in that there is a difference in one of the types in the referenced assembly from what was generated in the DataContract for the service  In my case  the service I was importing had newer  updated types from what I had in the shared assembly  This was not readily apparent because the type mentioned in the exception appeared to be the same  What was different was one of the nested complex types used by the type   There are other more complex scenarios that may trigger this type of exception and resulting blank reference cs  Here is one example   If you are experiencing this issue and you are not using generic types in your data contracts nor are you using IsReference   true  then I recommend verifying for certain that your shared types are exactly the same on your client and server  Otherwise  you will likely run into this issue

User · Answer

The technique that worked for me in my case  after reading these answers to no avail  was simply to comment out all of my contract  and uncomment bits until it doesn t work anymore  in a binary search fashion  That narrows down the offending bit of code   Then you just have to guess what s wrong with that code   Some error feedback in the tool would have helped  of course   I am writing a web service contract  I had a placeholder enum with no members  That s OK  But if I use it in a property of another class  and re-use the contract dll on the client  the codegen explodes with no error message  Running svcutil exe didn t help  it just failed to output a cs file without mentioning why

User · Answer

I ve been bashing my head for a whole day with this exact problem  I ve just fixed it  Here s how     The service had to run over SSL  i e  it s at https   mydomain com MyService svc   Adding a service reference to the WCF service on a development server worked just fine   Deploying the exact same build of the WCF service on the live production server  then switching to the client application and configuring the service reference to point to the live service displayed no errors but the app wouldn t build  It turns out that the service reference s Reference cs file was completely empty  Updating the service reference made no difference  Cleaning the solution didn t help  Restarting VS2010 made no difference  Creating a new blank solution  starting a console project and adding a service reference to the live service exhibited exactly the same problem   I didn t think it was due to conflicting types or anything  but what the heck - I reconfigured the WCF service reference by unchecking  Reuse types in all referenced assemblies   No joy  I put the check mark back   Next step was to try svcutil on the reference URL to see if that would help uncover the problem  Here s the command    svcutil  t code https   mydomain com MyService svc  d D  test   This produced the following   Microsoft  R  Service Model Metadata Tool  Microsoft  R  Windows  R  Communication Foundation  Version 4 0 30319 1  Copyright  c  Microsoft Corporation   All rights reserved   Attempting to download metadata from  https   mydomain com MyService svc  using WS-Metadata Exchange or DISCO  Error  Cannot import wsdl portType Detail  An exception was thrown while running a WSDL import extension  System ServiceModel Description DataContractSerializerMessageContractImporter Error  Schema with target namespace  http   mynamespace com    could not be found  XPath to Error Source    wsdl definitions  targetNamespace  http   mynamespace com     wsdl portType  name  IMyService     Error  Cannot import wsdl binding Detail  There was an error importing a wsdl portType that the wsdl binding is dependent on  XPath to wsdl portType    wsdl definitions  targetNamespace  http   mynamespace com     wsdl portType  name  IMyService   XPath to Error Source    wsdl definitions  targetNamespace  http   tempuri org    wsdl binding  name  WSHttpBinding IMyService     Error  Cannot import wsdl port Detail  There was an error importing a wsdl binding that the wsdl port is dependent on  XPath to wsdl binding    wsdl definitions  targetNamespace  http   tempuri org    wsdl binding  name  WSHttpBinding IMyService   XPath to Error Source    wsdl definitions  targetNamespace  http   tempuri org    wsdl service  name  MyService   wsdl port  name  WSHttpBinding IMyService     Generating files    Warning  No code was generated  If you were trying to generate a client  this could be because the metadata documents did not contain any valid contracts or services or because all contracts services were discovered to exist in  reference assemblies  Verify that you passed all the metadata documents to the tool   Warning  If you would like to generate data contracts from schemas make sure to use the  dataContractOnly option    That had me completely stumped  Despite heavy googling and getting really rather cross  and reconsidering a career as a bus driver  I finally considered why it worked OK on the development box  Could it be an IIS configuration issue   I remoted simultaneously into both the development and live boxes  and on each I fired up the IIS Manager  running IIS 7 5   Next  I went through each configuration setting on each box  comparing the values on each server   And there s the problem  Under  SSL Settings  for the site  make sure  Require SSL  is checked  and check the Client Certificates radio button for  Accept   Problem fixed

User · Answer

Thanks to John Saunders post above which gave me an idea to look into Error window  I was bagging all day my head and I was looking at Output window for any error    In my case the culprit was ISerializable  I have a DataContract class with DataMember property of type Exception  You cannot have any DataMember of type which has ISerializable keyword  In this Exception has ISerializable as soon as I removed it everything worked like a charm

User · Answer

I had this problem with a Silverlight 5 upgraded from a previous version   Even re-adding the service reference still gave me an empty Reference cs  I ended up having to create a brand new project and re-creating the service reference  This is something to try if you ve spent more than about half an hour on this  Even if you re determined to fix the original project you may want to try this just to see what happens and then work backwards to try to fix the problem   I never did figure out exactly what the problem was - but possibly something in the  csproj file wasn t upgraded  or some setting went wrong

User · Answer

As  dblood points out  the main pain is in the DataContractSerializer  that doens t correctly re-use the types  There are already some answers here so I ll start by adding some pro s and cons about these    The  IsReference  flag causes a lot of trouble  but removing it isn t always the answer  specifically  in situations with recursion    The underlying issue is that the data contract is somehow not the same as the type names  even though they sometimes are  huh  Yes  you read that right    Apparently the serializer is quite picky and it s very hard to find the real issue  Removing the  references checks  from the  Configure service reference  works  but leaves you with a multiple implementations  However  I often reuse SOAP interfaces across DLL s  Also  in most mature SOA s that I know  multiple services interfaces implement and extend the same interface classes  Removing  use referenced types  checks results in a situation where you cannot simply pass objects around anymore    Fortunately  if you are in control of your service  there is a simple solution that solves all these issues  This means you can still re-use service interfaces across DLL s - which is IMO a must-have for a proper solution  This is how the solution works    Create a separate interface DLL  In that DLL  include all DataContract and ServiceContract s  put ServiceContract s on your interfaces  Derive the server implementation from the interface  Use the same DLL to construct the client using your favorite method  For example  IMyInterface is the service contract interface    var httpBinding   new BasicHttpBinding    var identity   new DnsEndpointIdentity      var address   new EndpointAddress url  identity  new AddressHeaderCollection     var channel   new ChannelFactory lt IMyInterface gt  httpBinding  address   return channel CreateChannel       In other words  Don t use the  add service reference  functionality  but force WCF to use the  correct  service types by bypassing the proxy generation  After all  you already have these classes   Pro s    You bypass the svcutil exe process  which means you don t have any IsReference issues DataContract types and names are correct by definition  after all  both server and client use the very same definition  If you extend the API or use types from another DLL   1  and  2  still hold  so you won t run in any trouble there    Cons     A-sync methods are a pain  since you don t generate an a-sync proxy  As a result  I wouldn t recommend doing this in Silverlight applications

User · Answer

I faced similar issue yesterday during development  I found out I was using same namespace in 2 different versions of contracts    We ve 2 version of contracts for example version4 and version5  I ve copied all the contracts from version4 and renamed all the namespace from version4 to version5  While doing this I forgot to rename the namespace from v4 to v5 in one of the files  Due to namespace conflict  Reference cs file was empty   This issue is hard to troubleshoot as you don t get any error message while generating the service reference  To identify this issue I d manually validate all the new files I d created  There are other ways to solve this issue  This is the first step you should perform before going for other options

[c#] Sometimes adding a WCF Service Reference generates an empty reference.cs

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