OnConnect Method

Summary

Notifies the SCU that the connection attempt is complete.

Syntax

Objective-C

C++/CLI

protected virtual void OnConnect( 
   DicomExceptionCode error 
)

- (void)onConnect:(LTDicomErrorCode)error;

protected: 
virtual void OnConnect(  
   DicomExceptionCode error 
)

Parameters

error
An error code.

Remarks

A call to this method is generated on an SCU when an SCP calls Accept. It is generated whether or not the connection attempt is successful. It is also generated when a connection attempt has timed-out. To customize this method, you must derive a class from DicomNet and override this method.

A DICOM Association must be established between an SCU and an SCP before any DICOM messages or data can be transmitted between them. For more information on creating a DICOM Association, refer to Creating a DICOM Associate Connection.

Example

using Leadtools; 
using Leadtools.Dicom; 
 
 
[StructLayout(LayoutKind.Sequential)] 
public struct MSG 
{ 
   public IntPtr hwnd; 
   public uint message; 
   public IntPtr wParam; 
   public IntPtr lParam; 
   public uint time; 
   public System.Drawing.Point p; 
} 
 
public enum WaitReturn 
{ 
   Complete, 
   Timeout, 
} 
 
class Utils 
{ 
   [DllImport("user32.dll")] 
   [return: MarshalAs(UnmanagedType.Bool)] 
   static extern bool PeekMessage(out MSG lpMsg, IntPtr hWnd, 
                                  uint wMsgFilterMin, uint wMsgFilterMax, 
                                  uint wRemoveMsg); 
 
   [DllImport("user32.dll")] 
   static extern bool TranslateMessage([In] ref MSG lpMsg); 
   [DllImport("user32.dll")] 
   static extern IntPtr DispatchMessage([In] ref MSG lpmsg); 
 
   const uint PM_REMOVE = 1; 
 
   public static WaitReturn WaitForComplete(double mill, WaitHandle wh) 
   { 
      TimeSpan goal = new TimeSpan(DateTime.Now.AddMilliseconds(mill).Ticks); 
 
      do 
      { 
         MSG msg = new MSG(); 
 
         if (PeekMessage(out msg, IntPtr.Zero, 0, 0, PM_REMOVE)) 
         { 
            TranslateMessage(ref msg); 
            DispatchMessage(ref msg); 
         } 
 
         if (wh.WaitOne(new TimeSpan(0, 0, 0), false)) 
         { 
            return WaitReturn.Complete; 
         } 
 
         if (goal.CompareTo(new TimeSpan(DateTime.Now.Ticks)) < 0) 
         { 
            return WaitReturn.Timeout; 
         } 
 
      } while (true); 
   } 
} 
 
class Client : DicomNet 
{ 
   DicomExceptionCode _LastError = DicomExceptionCode.Success; 
   AutoResetEvent waitEvent = new AutoResetEvent(false); 
 
   public Client() 
       : base(null, DicomNetSecurityMode.None) 
   { 
   } 
 
   public DicomExceptionCode LastError 
   { 
      get 
      { 
         return _LastError; 
      } 
   } 
 
   public bool Wait() 
   { 
      WaitReturn ret; 
 
      _LastError = DicomExceptionCode.Success; 
      ret = Utils.WaitForComplete((5 * 60) * 1000, waitEvent); 
 
      return (ret == WaitReturn.Complete); 
   } 
 
   protected override void OnConnect(DicomExceptionCode error) 
   { 
      _LastError = error; 
      waitEvent.Set(); 
   } 
 
   protected override void OnReceiveAssociateAccept(DicomAssociate association) 
   { 
      waitEvent.Set(); 
   } 
 
   protected override void OnReceiveAssociateReject(DicomAssociateRejectResultType result, 
                                                    DicomAssociateRejectSourceType source, 
                                                    DicomAssociateRejectReasonType reason) 
   { 
      Debug.Assert(result == DicomAssociateRejectResultType.Permanent, "Result should be: " + DicomAssociateRejectResultType.Permanent.ToString()); 
      Debug.Assert(source == DicomAssociateRejectSourceType.User, "Source should be: " + DicomAssociateRejectSourceType.User.ToString()); 
      Debug.Assert(reason == DicomAssociateRejectReasonType.Limit, " Reason should be: " + DicomAssociateRejectReasonType.Limit.ToString()); 
      waitEvent.Set(); 
   } 
 
   protected override void OnReceiveReleaseResponse() 
   { 
      waitEvent.Set(); 
   } 
} 
 
class ServerConnection : DicomNet 
{ 
   public bool Fail = false; 
 
   public ServerConnection() 
       : base(null, DicomNetSecurityMode.None) 
   { 
   } 
 
   protected override void OnReceiveAssociateRequest(DicomAssociate association) 
   { 
      DicomAssociate retAssociation = new DicomAssociate(false); 
 
      if (Fail) 
      { 
         SendAssociateReject(DicomAssociateRejectResultType.Permanent, 
                             DicomAssociateRejectSourceType.User, 
                             DicomAssociateRejectReasonType.Limit); 
         return; 
      } 
 
      Debug.Assert(association.Called == "ServerTest", "Called AETitle should be ServerTest"); 
      Debug.Assert(association.Calling == "ClientTest", "Calling AETitle should be ClientTest"); 
      Debug.Assert(association.ImplementClass == "1.2.840.114257.1", "Implementation class should be 1.2.840.114257.1"); 
      Debug.Assert(association.ImplementationVersionName == "1", "Implementation version should be 1"); 
      Debug.Assert(association.MaxLength == 0x100000, "Max length should be 0x100000"); 
      Debug.Assert(association.GetAbstract(1) == DicomUidType.VerificationClass, "Presentation index 1 should be " + DicomUidType.VerificationClass); 
      Debug.Assert(association.GetTransfer(1, 0) == DicomUidType.ImplicitVRLittleEndian, "Abstract Syntax (1,0) should be " + DicomUidType.ImplicitVRLittleEndian); 
 
      // 
      // Build our Association Accept 
      // 
      retAssociation.Called = association.Called; 
      retAssociation.Calling = association.Calling; 
      retAssociation.ImplementClass = association.ImplementClass; 
      retAssociation.ImplementationVersionName = association.ImplementationVersionName; 
      for (int x = 0; x < association.PresentationContextCount; x++) 
      { 
         byte id = association.GetPresentationContextID(x); 
         string abSyntax = association.GetAbstract(id); 
         string trSyntax = DicomUidType.ImplicitVRLittleEndian; 
 
         retAssociation.AddPresentationContext(id, 0, abSyntax); 
         if (association.GetTransferCount(id) > 0) 
         { 
            trSyntax = association.GetTransfer(id, 0); 
         } 
         //Over here we can call retAssociation.SetAbstract to update the abstract 
         //syntax for any of the sresentation contexts 
         retAssociation.AddTransfer(id, trSyntax); 
         if (retAssociation.GetTransferCount(id) == 0) 
         { 
            // 
            // Presentation id doesn't have any abstract 
            //  syntaxes therefore we will reject it. 
            // 
            retAssociation.SetResult(id, DicomAssociateAcceptResultType.AbstractSyntax); 
            Debug.Assert(retAssociation.GetResult(id) == DicomAssociateAcceptResultType.AbstractSyntax, "Result should be: " + DicomAssociateAcceptResultType.AbstractSyntax.ToString()); 
         } 
 
 
         //  We can also call in here SetPresentationContextID if we would like  
         //  to change some of the presentation IDs 
         //  And SetTransfer to update the Transfer Syntax for a certian 
         //  presentation context. 
 
      } 
      SendAssociateAccept(retAssociation); 
   } 
 
   protected override void OnReceiveReleaseRequest() 
   { 
      SendReleaseResponse(); 
   } 
}; 
 
class Server : DicomNet 
{ 
   ServerConnection client; 
 
   public Server() 
       : base(null, DicomNetSecurityMode.None) 
   { 
   } 
 
   public bool Fail 
   { 
      get 
      { 
         if (client == null) 
            return false; 
 
         return client.Fail; 
      } 
 
      set 
      { 
         if (client != null) 
         { 
            client.Fail = value; 
         } 
      } 
   } 
 
   protected override void OnAccept(DicomExceptionCode error) 
   { 
      client = new ServerConnection(); 
 
      Accept(client); 
   } 
} 
 
public void SendAssociateRequestSample() 
{ 
   DicomEngine.Startup(); 
   DicomNet.Startup(); 
 
   using (Server server = new Server()) 
   { 
      using (Client client = new Client()) 
      { 
         // 
         // Connect to server 
         // 
         server.Listen("127.0.0.1", 104, 1); // start server 
         client.Connect(null, 1000, "127.0.0.1", 104); // connect to server 
         if (!client.Wait()) // wait for connection to finish 
         { 
            Debug.Fail("Connection timed out"); 
         } 
         Debug.Assert(client.LastError == DicomExceptionCode.Success, "Connection failed"); 
         Debug.Assert(client.IsConnected(), "Client not connected"); 
 
         // 
         // Send associate request 
         // 
         DicomAssociate associate = new DicomAssociate(true); 
 
         associate.Called = "ServerTest"; 
         associate.Calling = "ClientTest"; 
         associate.ImplementClass = "1.2.840.114257.1"; 
         associate.ImplementationVersionName = "1"; 
         associate.MaxLength = 0x100000; 
         //We can also call in here associate.Default() to initialize  
         //the association with default values. 
         associate.AddPresentationContext(1, 0, DicomUidType.VerificationClass); 
         associate.AddTransfer(1, DicomUidType.ImplicitVRLittleEndian); 
         client.SendAssociateRequest(associate); 
         if (!client.Wait()) // wait for connection to finish 
         { 
            Debug.Fail("SendAssociateRequest timed out"); 
         } 
 
         // 
         // SendReleaseRequest 
         // 
         client.SendReleaseRequest(); 
         if (!client.Wait()) // wait for connection to finish 
         { 
            Debug.Fail("SendAssociateRequest timed out"); 
         } 
 
         // 
         // Force association to send SendAssociateReject. This is for 
         // testing purposes only.  Only one association should be sent 
         // per connection. 
         // 
         server.Fail = true; 
         client.SendAssociateRequest(associate); 
         if (!client.Wait()) // wait for connection to finish 
         { 
            Debug.Fail("SendAssociateRequest timed out"); 
         } 
         server.Fail = false; 
 
         // 
         // SendReleaseRequest 
         // 
         client.SendReleaseRequest(); 
         if (!client.Wait()) // wait for connection to finish 
         { 
            Debug.Fail("SendAssociateRequest timed out"); 
         } 
 
         client.CloseForced(true); 
      } 
      server.CloseForced(true); 
   } 
 
   DicomEngine.Shutdown(); 
   DicomNet.Shutdown(); 
}

Requirements

Target Platforms

Reference

DicomNet Class

DicomNet Members

Connect(String,Int32,String,Int32) Method

Accept Method

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Help Version 23.0.2024.8.20

Leadtools.Dicom Assembly

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