I'm not very familiar how exactly C-GET implementation works out.I never had experience with it.

But so far what i know is; SCU sends c-get request.. Scp first responds with a storage-request in the same association... After each storage message, scp also sends c-get responses. If this implementation is true; your dvtk library codes should look like the following :

                public class myCgetSCU : DicomThread

                {

                    ThreadManager threadManager;

                    MainThread mainThread;

                    public myCgetSCU()

                    {

                    }

                    protected override void Execute()

                    {

                        // first load operations for dicom thread

                        // making these operations sometimes returns error if they are in the constructer.

                        // making them in execute method is safer...

                        threadManager = new ThreadManager();

                        mainThread = new MainThread();

                        mainThread.Initialize(threadManager);

                        this.Initialize(mainThread);

                        this.Options.LoadDefinitionFile("........ dvtk def file 1 for query retrieve ");

                        this.Options.LoadDefinitionFile("........ dvtk def file 2 for query retrieve ");

                        // .....

                        // .....

                        this.Options.LoadDefinitionFile("........ dvtk def file 1 for storage ");

                        this.Options.LoadDefinitionFile("........ dvtk def file 2 for storage ");

                        // .....

                        // .....

                        this.Options.AutoValidate = false;

                        this.Options.StorageMode = Dvtk.Sessions.StorageMode.AsMedia;

                        this.Options.RemoteAeTitle = "RemoteSCPAe";

                        this.Options.RemoteHostName = "RemoteIpAdress";

                        this.Options.RemotePort = 104;

                        this.MessageReceivedEvent += new MessageReceivedEventHandler(mySCU_MessageReceivedEvent);

                        // ------------------------------

                        // preapare your presentation contexts for association request...

                        string abstractSyntax = ".... sop class uid for query retrieve ";

                        string[] transferSyntaxes = new string[] { " tr.syntaxUid 1 your scu support", " tr.syntaxUid 2 your scu support", " .... " };

                        PresentationContext queryRetrieveContext = new PresentationContext( abstractSyntax, transferSyntaxes  );

                        // because you are using c-get instead of a C-move, you should

                        // create more presentaion contexes due to your supported storage sop classes

                        string abstractSyntaxStor1 = ".... sop class uid for query retrieve ";

                        string[] transferSyntaxesStor1 = new string[] { " tr.syntaxUid 1 your scu support", " tr.syntaxUid 2 your scu support", " .... " };

                        PresentationContext queryRetrieveContextStor1 = new PresentationContext(abstractSyntaxStor1, transferSyntaxesStor1);

                        // other storage presentation contexes..

                        // ..

                        // ..

                        // ..

                        // send your association request to scp

                        SendAssociateRq(new PresentationContext[] { queryRetrieveContext , queryRetrieveContextStor1 });

                        // wait for association response

                        ReceiveMessage();

                    }

                    void mySCU_MessageReceivedEvent(DvtkHighLevelInterface.Dicom.Messages.DicomProtocolMessage dicomProtocolMessage)

                    {

                        if (dicomProtocolMessage.IsAssociateAc)

                        {

                            // Thread will come here right after your association is accepted by remote scp

                            DicomMessage cGetRqMsg = new DvtkHighLevelInterface.Dicom.Messages.DicomMessage(DvtkData.Dimse.DimseCommand.CGETRQ);

                            cGetRqMsg.CommandSet.Set(DvtkData.Dimse.Tag.AFFECTED_SOP_CLASS_UID, DvtkData.Dimse.VR.UI, ".. query retrieve sop class uid");

                            cGetRqMsg.CommandSet.Set(DvtkData.Dimse.Tag.MESSAGE_ID, DvtkData.Dimse.VR.US, "1");

                            // ..... set other commandSet values due to dicom implementation

                            // .....

                            cGetRqMsg.DataSet.Set(DvtkData.Dimse.Tag.STUDY_INSTANCE_UID, DvtkData.Dimse.VR.UI, " .. study instance uid you request .. ");

                            // ..... set other dataSet values due to dicom implementation

                            // .....

                            Send(cGetRqMsg);

                            cGetRqMsg.DataSet.Clear();

                            cGetRqMsg = null;

                            ReceiveMessage();

                        }

                        else if (dicomProtocolMessage.IsDicomMessage)

                        {

                            if (dicomProtocolMessage.DicomMessage.CommandSet.DimseCommand == DvtkData.Dimse.DimseCommand.CGETRSP)

                            {

                                // Thread will come here after your previous c-get request is being responded by remote scp and after you recieved a store request

                                DicomMessage recievedMsg = dicomProtocolMessage.DicomMessage;

                                // you can get attribute values from recieved message like this...

                                string status = "" + recievedMsg.CommandSet["0x00000900"].Values[0];

                                if (status != "65280")

                                {

                                    // status = pending

                                    // storage operations will continue by the remote scp

                                    string numberOfRemaining = "" + recievedMsg.DataSet["0x00100010"].Values[0];

                                    // ... you can get other status informations like this one

                                    // ..

                                    // ..

                                    // you should wait for the next storage message

                                    ReceiveMessage();

                                }

                                else

                                {

                                    // all c-get responses are finished or error occured

                                    // send a release request

                                    SendReleaseRq();

                                    // wait for release response

                                    ReceiveMessage();

                                }

                            }

                            else if (dicomProtocolMessage.DicomMessage.CommandSet.DimseCommand == DvtkData.Dimse.DimseCommand.CSTORERQ)

                            {

                                // Thread will come here when remote scp sends a store request

                                // The whole dataset contains the dicom file dataset..

                                // you can create a dicom file here using a DicomFile class and set its dataset to a clone of recieved message.

                                DvtkHighLevelInterface.Dicom.Files.DicomFile file = new DvtkHighLevelInterface.Dicom.Files.DicomFile();

                                file.DataSet.CloneFrom(dicomProtocolMessage.DicomMessage.DataSet);

                                file.FileMetaInformation.MediaStorageSOPClassUID = "...."; // read it from dataset

                                file.FileMetaInformation.MediaStorageSOPInstanceUID = "...."; // read it from dataset

                                file.Write("where you want to save the file");

                                file.DataSet.Clear();

                                file = null;

                                // then you should wait for a c-get response

                                ReceiveMessage();

                            }

                        }

                    }

                }

/// 

in your application :

myCgetSCU scu = new myCgetSC();

myCgetSCU.Start();

Additional question :

Does HliScp class make some sort of validation stuff in the background?? Is there anything i can do to optimize its performace.

Here are the options i already set :

this.realSCU.Options.StorageMode = Dvtk.Sessions.StorageMode.NoStorage;

this.realSCU.Options.GenerateDetailedResults = false;     

this.realSCU.Options.LogChildThreadsOverview = false;            

this.realSCU.Options.LogThreadStartingAndStoppingInParent = false;

this.realSCU.Options.LogWaitingForCompletionChildThreads = false;

this.realSCU.Options.ShowResults = false;

this.realSCU.Options.StartAndStopResultsGatheringEnabled = false;

Hi. What is the proper way of stopping MessageIterator or MessageIterator based classes without causing an exception?? (such as HliScp ..)

When i call Stop() or StopCurrentThread() methods, it goes into a DicomMessageRecieve Exception because of its socket has been closed.

When i digg in the source codes, i noticed the "recieveMessage" variable and i understood that if i only set that variable to a "false" value, the internal while loop would release itself. But that didn't happen either. 

Right now, i am  handling the exception with a "try catch" statement on "base.Execute()"  line, and in the catch statement i am checking if Stop() command was calledor not before exception. But since application works multi threaded and hundreds of SCP classes are generated, those exceptions are quite disturbing.

Shortly; what is the best way of stopping the port listener without causing any Exception???