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SendCCancelRequest Method
See Also  Example
Leadtools.Dicom Namespace > DicomNet Class : SendCCancelRequest Method




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

Syntax

Visual Basic (Declaration) 
Public Sub SendCCancelRequest( _
   ByVal presentationID As Byte, _
   ByVal messageID As Integer _
) 
Visual Basic (Usage)Copy Code
Dim instance As DicomNet
Dim presentationID As Byte
Dim messageID As Integer
 
instance.SendCCancelRequest(presentationID, messageID)
C# 
public void SendCCancelRequest( 
   byte presentationID,
   int messageID
)
Managed Extensions for C++ 
public: void SendCCancelRequest( 
   byte presentationID,
   int messageID
) 
C++/CLI 
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.

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.

Visual BasicCopy Code
<StructLayout(LayoutKind.Sequential)> _
Public Structure MSG
    Public hwnd As IntPtr
    Public message As UInteger
    Public wParam As IntPtr
    Public lParam As IntPtr
    Public time As UInteger
    Public p As System.Drawing.Point
End Structure
Public Enum WaitReturn
    Complete
    Timeout
End Enum

Private Class Utils
    <DllImport("user32.dll")> _
    Shared Function PeekMessage(<System.Runtime.InteropServices.Out()> ByRef lpMsg As MSG, ByVal hWnd As IntPtr, ByVal wMsgFilterMin As UInteger, ByVal wMsgFilterMax As UInteger, ByVal wRemoveMsg As UInteger) As <MarshalAs(UnmanagedType.Bool)> Boolean
    End Function

    <DllImport("user32.dll")> _
    Shared Function TranslateMessage(ByRef lpMsg As MSG) As Boolean
    End Function
    <DllImport("user32.dll")> _
    Shared Function DispatchMessage(ByRef lpmsg As MSG) As IntPtr
    End Function

    Private Const PM_REMOVE As UInteger = 1

    Public Shared Function WaitForComplete(ByVal mill As Double, ByVal wh As WaitHandle) As WaitReturn
        Dim goal As TimeSpan = New TimeSpan(DateTime.Now.AddMilliseconds(mill).Ticks)

        Do
            Dim msg As MSG = New MSG()

            If PeekMessage(msg, IntPtr.Zero, 0, 0, PM_REMOVE) Then
                TranslateMessage(msg)
                DispatchMessage(msg)
            End If

            If wh.WaitOne(New TimeSpan(0, 0, 0), False) Then
                Return WaitReturn.Complete
            End If

            If goal.CompareTo(New TimeSpan(DateTime.Now.Ticks)) < 0 Then
                Return WaitReturn.Timeout
            End If

        Loop While True
    End Function
End Class

Private Class Client : Inherits DicomNet
    Private _LastError As DicomExceptionCode = DicomExceptionCode.Success
    Private waitEvent As AutoResetEvent = New AutoResetEvent(False)

    Public Sub New()
        MyBase.New(Nothing, DicomNetSecurityeMode.None)
    End Sub

    Public ReadOnly Property LastError() As DicomExceptionCode
        Get
            Return _LastError
        End Get
    End Property

    Public Function Wait() As Boolean
        Dim ret As WaitReturn

        _LastError = DicomExceptionCode.Success
        ret = Utils.WaitForComplete((5 * 60) * 1000, waitEvent)

        Return (ret = WaitReturn.Complete)
    End Function

    Protected Overrides Sub OnConnect(ByVal [error] As DicomExceptionCode)
        _LastError = [error]
        waitEvent.Set()
    End Sub

    Protected Overrides Sub OnReceiveAssociateAccept(ByVal association As DicomAssociate)
        waitEvent.Set()
    End Sub

    Protected Overrides Sub OnClose(ByVal [error] As DicomExceptionCode, ByVal net As DicomNet)
        waitEvent.Set()
    End Sub
End Class

Private Class ServerConnection : Inherits DicomNet
    Public Sub New()
        MyBase.New(Nothing, DicomNetSecurityeMode.None)
    End Sub

    Protected Overrides Sub OnReceiveAssociateRequest(ByVal association As DicomAssociate)
        Dim retAssociation As DicomAssociate = 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 = &H100000, "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
        Dim x As Integer = 0
        Do While x < association.PresentationContextCount
            Dim id As Byte = association.GetPresentationContextID(x)
            Dim abSyntax As String = association.GetAbstract(id)
            Dim trSyntax As String = DicomUidType.ImplicitVRLittleEndian

            retAssociation.AddPresentationContext(id, 0, abSyntax)
            If association.GetTransferCount(id) > 0 Then
                trSyntax = association.GetTransfer(id, 0)
            End If

            retAssociation.AddTransfer(id, trSyntax)
            x += 1
        Loop
        SendAssociateAccept(retAssociation)
    End Sub

    Protected Overrides Sub OnReceiveCCancelRequest(ByVal presentationID As Byte, ByVal messageID As Integer)
        Debug.Assert(presentationID = 1, "Presentation ID should be 1")
        Debug.Assert(messageID = 1, "Message ID should be 1")
        Close()
    End Sub
End Class

Private Class Server : Inherits DicomNet
    Private client As ServerConnection

    Public Sub New()
        MyBase.New(Nothing, DicomNetSecurityeMode.None)
    End Sub

    Protected Overrides Sub OnAccept(ByVal [error] As DicomExceptionCode)
        client = New ServerConnection()

        Accept(client)
    End Sub
End Class



Public Sub SendCCancleRequestSample()
    DicomEngine.Startup()
    DicomNet.Startup()

    Using server As Server = New Server()
        Using client As Client = New Client()
            '
            ' Connect to server
            '
            server.Listen("127.0.0.1", 104, 1) ' start server
            client.Connect(Nothing, 1000, "127.0.0.1", 104) ' connect to server
            If (Not client.Wait()) Then ' wait for connection to finish
                Debug.Fail("Connection timed out")
            End If
            Debug.Assert(client.LastError = DicomExceptionCode.Success, "Connection failed")
            Debug.Assert(client.IsConnected(), "Client not connected")

            '
            ' Send associate request
            '
            Dim associate As DicomAssociate = New DicomAssociate(True)

            associate.Called = "ServerTest"
            associate.Calling = "ClientTest"
            associate.ImplementClass = "1.2.840.114257.1"
            associate.ImplementationVersionName = "1"
            associate.MaxLength = &H100000
            associate.AddPresentationContext(1, 0, DicomUidType.VerificationClass)
            associate.AddTransfer(1, DicomUidType.ImplicitVRLittleEndian)
            client.SendAssociateRequest(associate)
            If (Not client.Wait()) Then ' wait for connection to finish
                Debug.Fail("SendAssociateRequest timed out")
            End If

            Dim p As IntPtr = New IntPtr(5)
            client.SendCCancelRequest(1, 1)
            If (Not client.Wait()) Then ' wait for SendNonSecureISCL to finish
                Debug.Fail("SendCCancelRequest timed out")
            End If
            If client.IsConnected() Then
                client.CloseForced(True)
            End If
        End Using
        server.CloseForced(True)
    End Using

    DicomEngine.Shutdown()
    DicomNet.Shutdown()
End Sub
C#Copy Code
[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, DicomNetSecurityeMode.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, DicomNetSecurityeMode.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, DicomNetSecurityeMode.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(); 
}

Remarks

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

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

Leadtools.Dicom requires a Medical toolkit license and unlock key. For more information, refer to: Raster Pro/Document/Medical Features