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



net
A DicomNet object that represents the client (the SCU).
net
A DicomNet object that represents the client (the SCU).
Accepts a connection request from an SCU.

Syntax

Visual Basic (Declaration) 
Public Sub Accept( _
   ByVal net As DicomNet _
)
Visual Basic (Usage)Copy Code
Dim instance As DicomNet
Dim net As DicomNet
 
instance.Accept(net)
C# 
public void Accept( 
   DicomNet net
)
C++/CLI 
public:
void Accept( 
   DicomNet^ net
)

Parameters

net
A DicomNet object that represents the client (the SCU).

Example

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 OnReceiveAssociateReject(ByVal result As DicomAssociateRejectResultType, ByVal source As DicomAssociateRejectSourceType, ByVal reason As DicomAssociateRejectReasonType)
        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()
    End Sub

    Protected Overrides Sub OnReceiveReleaseResponse()
        waitEvent.Set()
    End Sub
End Class

Private Class ServerConnection : Inherits DicomNet
    Public Fail As Boolean = False

    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)

        If Fail Then
            SendAssociateReject(DicomAssociateRejectResultType.Permanent, DicomAssociateRejectSourceType.User, DicomAssociateRejectReasonType.Limit)
            Return
        End If

        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
            '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 Then
               '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())
            End If


            ' 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.

            x += 1
        Loop
        SendAssociateAccept(retAssociation)
    End Sub

    Protected Overrides Sub OnReceiveReleaseRequest()
        SendReleaseResponse()
    End Sub
End Class

Private Class Server : Inherits DicomNet
    Private client As ServerConnection

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

    Public Property Fail() As Boolean
        Get
            If client Is Nothing Then
                Return False
            End If

            Return client.Fail
        End Get

        Set(ByVal value As Boolean)
            If Not client Is Nothing Then
                client.Fail = value
            End If
        End Set
    End Property

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

        Accept(client)
    End Sub
End Class


Public Sub SendAssociateRequestSample()
    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
            '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 (Not client.Wait()) Then ' wait for connection to finish
                Debug.Fail("SendAssociateRequest timed out")
            End If

            '
            ' SendReleaseRequest
            '
            client.SendReleaseRequest()
            If (Not client.Wait()) Then ' wait for connection to finish
                Debug.Fail("SendAssociateRequest timed out")
            End If

            '
            ' 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 (Not client.Wait()) Then ' wait for connection to finish
                Debug.Fail("SendAssociateRequest timed out")
            End If
            server.Fail = False

            '
            ' SendReleaseRequest
            '
            client.SendReleaseRequest()
            If (Not client.Wait()) Then ' wait for connection to finish
                Debug.Fail("SendAssociateRequest timed out")
            End If

            client.CloseForced(True)
        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 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, DicomNetSecurityeMode.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, DicomNetSecurityeMode.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(); 
}

Remarks

When an SCU requests a connection by calling Connect, a call to the OnAccept method is generated on the SCP. Within the OnAccept method, the SCP can decide whether to accept the connection or not. If the connection is accepted, Accept is called. This generates a call to the OnConnect method on the SCU, letting the SCU know the connection has been made.

You should always accept a connection request. Once the connection is made you can check the SCU and close the connection if you do not wish to maintain it. Since the connection requests are queued, if you do not accept a connection, it remains in the queue. When the next request is received, it is placed in the queue behind the first request. Calling Accept at this point will connect the first request, not the second, since the first request is still in the queue.

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

See Also

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