SendCCancelRequest Method

Summary

Sends a C-CANCEL-REQ message to a peer member of a connection.

Syntax

C++/CLI

public void SendCCancelRequest( 
   byte presentationID, 
   int messageID 
)

public: 
void SendCCancelRequest(  
   byte presentationID, 
   int messageID 
)

Parameters

presentationID
The Presentation Context ID. The ID provides information about both the class type of the data and the Transfer Syntax to use when transferring the data.

messageID
The Message ID. Each message sent by a member of a connection should have a unique ID. Since a member of a connection may send several messages, this ID allows that member to identify when a specific request has been completed.

Remarks

Calling this method generates a call to OnReceiveCCancelRequest on the SCP.

Example

This is a comprehensive sample that shows how to process a DICOM C-Cancel operation on both the SCP (server) and the SCU (client) sides.

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 OnClose(DicomExceptionCode error, DicomNet net) 
   { 
      waitEvent.Set(); 
   } 
} 
 
class ServerConnection : DicomNet 
{ 
   public ServerConnection() 
       : base(null, DicomNetSecurityMode.None) 
   { 
   } 
 
   protected override void OnReceiveAssociateRequest(DicomAssociate association) 
   { 
      DicomAssociate retAssociation = new DicomAssociate(false); 
 
      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); 
         } 
 
         retAssociation.AddTransfer(id, trSyntax); 
      } 
      SendAssociateAccept(retAssociation); 
   } 
 
   protected override void OnReceiveCCancelRequest(byte presentationID, int messageID) 
   { 
      Debug.Assert(presentationID == 1, "Presentation ID should be 1"); 
      Debug.Assert(messageID == 1, "Message ID should be 1"); 
      Close(); 
   } 
} 
 
class Server : DicomNet 
{ 
   ServerConnection client; 
 
   public Server() 
       : base(null, DicomNetSecurityMode.None) 
   { 
   } 
 
   protected override void OnAccept(DicomExceptionCode error) 
   { 
      client = new ServerConnection(); 
 
      Accept(client); 
   } 
} 
 
public void SendCCancleRequestSample() 
{ 
   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; 
         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"); 
         } 
 
         IntPtr p = new IntPtr(5); 
         client.SendCCancelRequest(1, 1); 
         if (!client.Wait()) // wait for SendNonSecureISCL to finish 
         { 
            Debug.Fail("SendCCancelRequest timed out"); 
         } 
         if (client.IsConnected()) 
            client.CloseForced(true); 
      } 
      server.CloseForced(true); 
   } 
 
   DicomEngine.Shutdown(); 
   DicomNet.Shutdown(); 
}

Requirements

Target Platforms

Reference

DicomNet Class

DicomNet Members

OnReceiveCCancelRequest Method

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Help Version 23.0.2024.8.20

Leadtools.Dicom Assembly

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