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SendCFindRequest Method
See Also 
Leadtools.Dicom Namespace > DicomNet Class : SendCFindRequest 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.
affectedClass
The class affected by the request. This will be a SOP Class or a Meta SOP Class.
priority
The priority level of the message. The Service Class Provider may or may not support priority. Therefore, setting this parameter may or may not have any effect.
dataSet
A DicomDataSet object that contains the Data Set to be found.
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.
affectedClass
The class affected by the request. This will be a SOP Class or a Meta SOP Class.
priority
The priority level of the message. The Service Class Provider may or may not support priority. Therefore, setting this parameter may or may not have any effect.
dataSet
A DicomDataSet object that contains the Data Set to be found.
Sends a C-FIND-REQ message to a peer member of a connection.

Syntax

Visual Basic (Declaration) 
Public Sub SendCFindRequest( _
   ByVal presentationID As Byte, _
   ByVal messageID As Integer, _
   ByVal affectedClass As String, _
   ByVal priority As DicomCommandPriorityType, _
   ByVal dataSet As DicomDataSet _
) 
Visual Basic (Usage)Copy Code
Dim instance As DicomNet
Dim presentationID As Byte
Dim messageID As Integer
Dim affectedClass As String
Dim priority As DicomCommandPriorityType
Dim dataSet As DicomDataSet
 
instance.SendCFindRequest(presentationID, messageID, affectedClass, priority, dataSet)
C# 
public void SendCFindRequest( 
   byte presentationID,
   int messageID,
   string affectedClass,
   DicomCommandPriorityType priority,
   DicomDataSet dataSet
)
C++/CLI 
public:
void SendCFindRequest( 
   byte presentationID,
   int messageID,
   String^ affectedClass,
   DicomCommandPriorityType priority,
   DicomDataSet^ dataSet
) 

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.
affectedClass
The class affected by the request. This will be a SOP Class or a Meta SOP Class.
priority
The priority level of the message. The Service Class Provider may or may not support priority. Therefore, setting this parameter may or may not have any effect.
dataSet
A DicomDataSet object that contains the Data Set to be found.

Example

This is a comprehensive sample that shows how to process a DICOM C-Find 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 OnReceiveReleaseResponse()
        waitEvent.Set()
    End Sub

    Protected Overrides Sub OnReceiveCFindResponse(ByVal presentationID As Byte, ByVal messageID As Integer, ByVal affectedClass As String, ByVal status As DicomCommandStatusType, ByVal dataSet As DicomDataSet)
        Debug.Assert(status = DicomCommandStatusType.Success, "Status should be success")
        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 OnReceiveReleaseRequest()
        SendReleaseResponse()
    End Sub

    Protected Overrides Sub OnReceiveCFindRequest(ByVal presentationID As Byte, ByVal messageID As Integer, ByVal affectedClass As String, ByVal priority As DicomCommandPriorityType, ByVal dataSet As DicomDataSet)
        Dim element As DicomElement

        Debug.Assert(Not dataSet Is Nothing, "Dataset should not be null")
        Debug.Assert(priority = DicomCommandPriorityType.Medium, "Priority should be medium")

        '
        ' Check dataset
        '
        element = dataSet.FindFirstElement(Nothing, DicomTag.QueryRetrieveLevel, True)
        Debug.Assert(Not element Is Nothing, "Element (QueryRetrieveLevel) should not be null")
        Debug.Assert(dataSet.GetStringValue(element, 0) = "PATIENT", "QueryRetrieveLevel should be PATIENT")

        element = dataSet.FindFirstElement(Nothing, DicomTag.PatientName, True)
        Debug.Assert(Not element Is Nothing, "Element (PatientName) should not be null")
        Debug.Assert(dataSet.GetStringValue(element, 0) = "TEST", "PatientName should be TEST")

        element = dataSet.FindFirstElement(Nothing, DicomTag.PatientID, True)
        Debug.Assert(Not element Is Nothing, "Element (PatientID) should not be null")
        Debug.Assert(dataSet.GetStringValue(element, 0) = "ID", "PatientID should be ID")

        '
        ' Normally you would create a dataset that patches the query.
        '  we will send back the same dataset here..
        '
        SendCFindResponse(presentationID, messageID, affectedClass, DicomCommandStatusType.Success, dataSet)
    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 SendCFindRequestSample()
    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)
            associate.AddPresentationContext(3, 0, DicomUidType.PatientRootQueryFind)
            associate.AddTransfer(3, DicomUidType.ImplicitVRLittleEndian)
            client.SendAssociateRequest(associate)
            If (Not client.Wait()) Then ' wait for connection to finish
                Debug.Fail("SendAssociateRequest timed out")
            End If

            Dim pid As Byte = client.Association.FindAbstract(DicomUidType.PatientRootQueryFind)
            Dim ds As DicomDataSet = New DicomDataSet()
            Dim element As DicomElement

            '
            ' Set up the find parameters
            '
            ds.Initialize(DicomClassType.PatientRootQueryPatient, DicomDataSetInitializeType.ExplicitVRLittleEndian)
            element = ds.FindFirstElement(Nothing, DicomTag.QueryRetrieveLevel, True)
            If element Is Nothing Then
                element = ds.InsertElement(Nothing, False, DicomTag.QueryRetrieveLevel, DicomVRType.UN, False, 0)
            End If
            ds.SetStringValue(element, "PATIENT", DicomCharacterSetType.Default)

            element = ds.FindFirstElement(Nothing, DicomTag.PatientName, True)
            If element Is Nothing Then
                element = ds.InsertElement(Nothing, False, DicomTag.PatientName, DicomVRType.UN, False, 0)
            End If
            ds.SetStringValue(element, "TEST", DicomCharacterSetType.Default)

            element = ds.FindFirstElement(Nothing, DicomTag.PatientID, True)
            If element Is Nothing Then
                element = ds.InsertElement(Nothing, False, DicomTag.PatientID, DicomVRType.UN, False, 0)
            End If
            ds.SetStringValue(element, "ID", DicomCharacterSetType.Default)

            client.SendCFindRequest(pid, 2, DicomUidType.PatientRootQueryFind, DicomCommandPriorityType.Medium, ds)
            If (Not client.Wait()) Then ' wait for CFind to finish
                Debug.Fail("SendCFindRequest 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 OnReceiveReleaseResponse()
    {
        waitEvent.Set();
    }

    protected override void OnReceiveCFindResponse(byte presentationID, int messageID, string affectedClass, DicomCommandStatusType status, DicomDataSet dataSet)
    {                   
        Debug.Assert(status == DicomCommandStatusType.Success, "Status should be success");
        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 OnReceiveReleaseRequest()
    {
        SendReleaseResponse();
    }

    protected override void OnReceiveCFindRequest(byte presentationID, int messageID, string affectedClass, DicomCommandPriorityType priority, DicomDataSet dataSet)
    {
        DicomElement element;                    

        Debug.Assert(dataSet != null, "Dataset should not be null");
        Debug.Assert(priority == DicomCommandPriorityType.Medium, "Priority should be medium");

        //
        // Check dataset
        //
        element = dataSet.FindFirstElement(null, DicomTag.QueryRetrieveLevel, true);
        Debug.Assert(element != null, "Element (QueryRetrieveLevel) should not be null");
        Debug.Assert(dataSet.GetStringValue(element, 0) == "PATIENT", "QueryRetrieveLevel should be PATIENT");

        element = dataSet.FindFirstElement(null, DicomTag.PatientName, true);
        Debug.Assert(element != null, "Element (PatientName) should not be null");
        Debug.Assert(dataSet.GetStringValue(element, 0) == "TEST", "PatientName should be TEST");

        element = dataSet.FindFirstElement(null, DicomTag.PatientID, true);
        Debug.Assert(element != null, "Element (PatientID) should not be null");
        Debug.Assert(dataSet.GetStringValue(element, 0) == "ID", "PatientID should be ID");

        //
        // Normally you would create a dataset that patches the query.
        //  we will send back the same dataset here..
        //
        SendCFindResponse(presentationID, messageID, affectedClass, DicomCommandStatusType.Success, dataSet);
    }
}

class Server : DicomNet
{
    ServerConnection client;

    public Server()
        : base(null, DicomNetSecurityeMode.None)
    {
    }

    protected override void OnAccept(DicomExceptionCode error)
    {
        client = new ServerConnection();

        Accept(client);
    }
}



public void SendCFindRequestSample()
{
    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);
            associate.AddPresentationContext(3, 0, DicomUidType.PatientRootQueryFind);
            associate.AddTransfer(3, DicomUidType.ImplicitVRLittleEndian);
            client.SendAssociateRequest(associate);
            if (!client.Wait()) // wait for connection to finish
            {
                Debug.Fail("SendAssociateRequest timed out");
            }

            byte pid = client.Association.FindAbstract(DicomUidType.PatientRootQueryFind);
            DicomDataSet ds = new DicomDataSet();
            DicomElement element;

            //
            // Set up the find parameters
            //
            ds.Initialize(DicomClassType.PatientRootQueryPatient, DicomDataSetInitializeType.ExplicitVRLittleEndian);
            element = ds.FindFirstElement(null, DicomTag.QueryRetrieveLevel, true);
            if (element == null)
            {
               element = ds.InsertElement(null, false, DicomTag.QueryRetrieveLevel, DicomVRType.UN, false, 0);
            }
            ds.SetStringValue(element, "PATIENT", DicomCharacterSetType.Default);

            element = ds.FindFirstElement(null, DicomTag.PatientName, true);
            if (element == null)
            {
               element = ds.InsertElement(null, false, DicomTag.PatientName, DicomVRType.UN, false, 0);
            }
            ds.SetStringValue(element, "TEST", DicomCharacterSetType.Default);

            element = ds.FindFirstElement(null, DicomTag.PatientID, true);
            if (element == null)
            {
               element = ds.InsertElement(null, false, DicomTag.PatientID, DicomVRType.UN, false, 0);
            }
            ds.SetStringValue(element, "ID", DicomCharacterSetType.Default);

            client.SendCFindRequest(pid, 2, DicomUidType.PatientRootQueryFind, DicomCommandPriorityType.Medium, ds);
            if (!client.Wait()) // wait for CFind to finish
            {
                Debug.Fail("SendCFindRequest timed out");
            }

            client.CloseForced(true);
        }
        server.CloseForced(true);
    }

    DicomEngine.Shutdown();
    DicomNet.Shutdown();
}
SilverlightCSharpCopy Code
SilverlightVBCopy Code

Remarks

Calling this method generates a call to Leadtools.Dicom.DicomNet.OnReceiveCFindRequest on the SCP. The SCP should respond by calling Leadtools.Dicom.DicomNet.SendCFindResponse which will generate a call to Leadtools.Dicom.DicomNet.OnReceiveCFindResponse.

You must create a Data Set and insert elements corresponding to the data you wish to find. This Data Set is then passed to the method.

Requirements

Target Platforms: Silverlight 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7, MAC OS/X (Intel Only)

See Also

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