Jak vytvo�it RealTimeData server pro Excel

Aplikace Microsoft Excel poskytuje nov� funkce listu RTD, kter� umo��uje vol�n� komponent modelu COM) Automation server z d�vodu na��t�n� dat v re�ln�m �ase. Tento �l�nek popisuje, jak vytvo�it RealTimeData Server pro pou�it� s RTD funkce aplikace Excel pomoc� jazyka.

Funkce listu RTD m� n�sleduj�c� syntaxi: Prvn� argument ProgID p�edstavuje programov� identifik�tor (ProgID) serveru RealTimeData. Server argument ozna�uje n�zev po��ta�e, na kter�m je spu�t�n server RealTimeData; tohoto argumentu m��e b�t nulov� �et�zec nebo vynech�n, pokud je server RealTimeData spustit m�stn�. Zb�vaj�c� argumenty jednodu�e p�edstavuj� parametry odeslat na server RealTimeData; ka�d� jedine�nou kombinaci t�chto parametr� p�edstavuje jedno "t�ma, id t�matu"kter� m� p�idru�en�"." Parametry jsou rozli�ov�na mal� a velk� p�smena. N�sleduj�c� ilustruje nap��klad vol�n� server RTD, kter� by v�sledkem t�i samostatn� t�ma ID: V po�ad� pro automatizaci server COM b�t RealTimeData Server pro pou�it� s RTD funkce aplikace Excel jej mus� implementovat rozhran� IRTDServer. Server mus� implementovat v�echny metody IRTDServer:

ServerStartServerTerminateConnectDataDisconnectDataPrezen�n� sign�lRefreshData

Vytvo�it server uk�zkov� RealTimeData

N�sleduj�c� p��klad zn�zor�uje zp�sob vytvo�en� a pou�it� RealTimeData serveru s aplikac� Microsoft Excel 2002. Tento server poskytuje jednodu�e ��ta� aktualizov�ny ka�d�ch 10 sekund na listu. P�ijme server a� dva �et�zce t�ma. Prvn� �et�zec t�matu m��e b�t ?ady AAA BBB a CCC; jin� �et�zec t�matu pova�ov�ny za neplatn� a server vr�t� # hodnota! Chcete-li funkci RTD. Druh� �et�zec je ��seln� hodnota, kter� p�edstavuje zp�sob vr�cen� hodnota zv��ena. Pokud je druh� �et�zec vynech�n, v�choz� hodnota p��r�stku 1. Pokud nen� druh� �et�zec ��seln�, vr�t� server # NUM! Chcete-li funkci RTD.

1. Spu�t�n� nov�ho projektu ActiveX DLL v jazyka.
2. V nab�dce projekt klepn�te na p��kaz odkazy, vyberte objektov� knihovna pro verzi aplikace Excel a potom klepn�te na tla��tko OK. Nap��klad vyberte jednu z n�sleduj�c�ch:
   • Microsoft Office Excel 2007 vyberte 12.0 objektov� knihovny Microsoft Excel.
   • Microsoft Office Excel 2003 vyberte Microsoft Excel 11.0 Object Library.
   • Aplikaci Excel 2002 vyberte Objektov� knihovny Microsoft Excel 10.0.
3. V nab�dce projekt klepn�te na p��kaz Project1 vlastnosti. Zm�nit N�zev projektuExcelRTD a potom klepn�te na tla��tko OK.
4. Zm��te vlastnost n�zev modulu t��dy Class1RTDFunctions. P�idejte n�sleduj�c� k�d RTDFunctions:

   Option Explicit
   
   Implements IRtdServer  'Interface allows Excel to contact this RealTimeData server
   
   Private m_colTopics As Collection
       
   Private Function IRtdServer_ConnectData(ByVal TopicID As Long, Strings() As Variant, GetNewValues As Boolean) As Variant
       '** ConnectData is called whenever a new RTD topic is requested
       
       'Create a new topic class with the given TopicId and string and add it to the
       'm_colTopics collection
       Dim oTopic As New Topic
       m_colTopics.Add oTopic, CStr(TopicID)
       oTopic.TopicID = TopicID
       oTopic.TopicString = Strings(0)
       If UBound(Strings) >= 1 Then oTopic.SetIncrement Strings(1)
       
       'For this example, the initial value for a new topic is always 0
       IRtdServer_ConnectData = oTopic.TopicValue
       
       Debug.Print "ConnectData", TopicID
   End Function
   
   Private Sub IRtdServer_DisconnectData(ByVal TopicID As Long)
      '** DisconnectData is called whenever a specific topic is not longer needed
      
      'Remove the topic from the collection
      m_colTopics.Remove CStr(TopicID)
      
      Debug.Print "DisconnectData", TopicID
   End Sub
   
   Private Function IRtdServer_Heartbeat() As Long
       '** Called by Excel if the heartbeat interval has elapsed since the last time
       '   Excel was called with UpdateNotify.
       Debug.Print "HeartBeat"
   End Function
   
   Private Function IRtdServer_RefreshData(TopicCount As Long) As Variant()
       '** Called when Excel is requesting a refresh on topics. RefreshData will be called
       '   after an UpdateNotify has been issued by the server. This event should:
       '   - supply a value for TopicCount (number of topics to update)
       '   - return a two dimensional variant array containing the topic ids and the
       '     new values of each.
      
       Dim oTopic As Topic, n As Integer
       ReDim aUpdates(0 To 1, 0 To m_colTopics.Count - 1) As Variant
       For Each oTopic In m_colTopics
           oTopic.Update
           aUpdates(0, n) = oTopic.TopicID
           aUpdates(1, n) = oTopic.TopicValue
           n = n + 1
       Next
       TopicCount = m_colTopics.Count
       IRtdServer_RefreshData = aUpdates
      
      Debug.Print "RefreshData", TopicCount & " topics updated"
   End Function
   
   Private Function IRtdServer_ServerStart(ByVal CallbackObject As Excel.IRTDUpdateEvent) As Long
       '** ServerStart is called when the first RTD topic is requested
       
       Set oCallBack = CallbackObject
       Set m_colTopics = New Collection
       g_TimerID = SetTimer(0, 0, TIMER_INTERVAL, AddressOf TimerCallback)
       If g_TimerID > 0 Then IRtdServer_ServerStart = 1       'Any value <1 indicates failure.
       
       Debug.Print "ServerStart"
   End Function
   
   Private Sub IRtdServer_ServerTerminate()
       '** ServerTerminate is called when no more topics are needed by Excel.
       
       KillTimer 0, g_TimerID
   
       '** Cleanup any remaining topics. This is done here since 
       '   IRtdServer_DisconnectData is only called if a topic is disconnected 
       '   while the book is open. Items left in the collection when we terminate
       '   are those topics left running when the workbook was closed.
   
       Dim oTopic As Topic
       For Each oTopic In m_colTopics
           m_colTopics.Remove CStr(oTopic.TopicID)
           Set oTopic = Nothing
       Next
   
       Debug.Print "ServerTerminate"
     
   End Sub
   
   					

5. V nab�dce projekt klepn�te na tla��tko P�idat modul t��dy. Zm�nit modul t��dy vlastnost n�zevt�matu a zm��te vlastnost InstancingPrivate. Modul t��dy t�ma p�idejte n�sleduj�c� k�d:

   Option Explicit
   
   Private m_TopicID As Long
   Private m_TopicString As String
   Private m_Value As Variant
   Private m_IncrementVal As Long
   
   Private Sub Class_Initialize()
       m_Value = 0
       m_IncrementVal = 1
   End Sub
   
   Friend Property Let TopicID(ID As Long)
       m_TopicID = ID
   End Property
   
   Friend Property Get TopicID() As Long
       TopicID = m_TopicID
   End Property
   
   Friend Property Let TopicString(s As String)
       s = UCase(s)
       If s = "AAA" Or s = "BBB" Or s = "CCC" Then
           m_TopicString = s
       Else
           m_Value = CVErr(xlErrValue) 'Return #VALUE if not one of the listed topics
       End If
   End Property
   
   Friend Sub Update()
       On Error Resume Next 'the next operation will fail if m_Value is an error (like #NUM or #VALUE)
       m_Value = m_Value + m_IncrementVal
   End Sub
   
   Friend Sub SetIncrement(v As Variant)
       On Error Resume Next
       m_IncrementVal = CLng(v)
       If Err <> 0 Then
           m_Value = CVErr(xlErrNum) 'Return #NUM if Increment value is not numeric
       End If
   End Sub
   
   Friend Property Get TopicValue() As Variant
       If Not (IsError(m_Value)) Then
           TopicValue = m_TopicString & ": " & m_Value
       Else
           TopicValue = m_Value
       End If
   End Property
   					

6. V nab�dce projekt vyberte P�idat modul. Nov� modul p�idejte n�sleduj�c� k�d:

   Public Declare Function SetTimer Lib "user32" (ByVal hWnd As Long, _
   ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As Long) As Long
   
   Public Declare Function KillTimer Lib "user32" (ByVal hWnd As Long, ByVal nIDEvent As Long) As Long
   
   Public Const TIMER_INTERVAL = 5000
   Public oCallBack As Excel.IRTDUpdateEvent
   Public g_TimerID As Long
   
   Public Sub TimerCallback(ByVal hWnd As Long, ByVal uMsg As Long, ByVal idEvent As Long, ByVal dwTime As Long)
       oCallBack.UpdateNotify
   End Sub
   					

7. V nab�dce soubor klepn�te na tla��tko Vytvo�it ExcelRTD.dll sestaven� komponenty.

Pou��t RTD server v aplikaci Excel

1. Spus�te nov� se�it v aplikaci Microsoft Excel.
2. Zadejte n�sleduj�c� vzorec v bu�ce A1 a stiskn�te kl�vesu ENTER:
   = RTD("ExcelRTD.RTDFunctions",,"AAA", 5)
   Po��te�n� vr�cen� hodnota je � ?ady AAA: 0 ". Po p�ti sekund�ch aktualizuje hodnotu na � ?ady AAA: 10 "a po 10 sekund�ch aktualizuje hodnotu"AAA:15"a tak d�le.
   
   
3. V bu�ce A2 zadejte n�sleduj�c� vzorec a stiskn�te kl�vesu ENTER:
   = RTD("ExcelRTD.RTDFunctions",,"BBB", 3)
   Po��te�n� vr�cen� hodnota je � BBB: 0 ". Hodnota bu�ky zv��� o 3 ka�d�ch p�t sekund.
   
   
4. V bu�ce A3 zadejte n�sleduj�c� vzorec a stiskn�te kl�vesu ENTER:
   = RTD("ExcelRTD.RTDFunctions",,"AAA", 5)
   Po��te�n� vr�cen� hodnota odpov�d� obsah bu�ky A1, proto�e to je stejn� "t�ma" pou��van� A1.
   
   
5. V bu�ce A4 zadejte n�sleduj�c� vzorec a stiskn�te kl�vesu ENTER:
   = RTD("ExcelRTD.RTDFunctions",,"AAA", 10)
   Po��te�n� vr�cen� hodnota je � ?ady AAA: 0. "ka�d�ch p�t sekund p��r�stc�ch hodnotu bu�ky, stejn� jako jin� bu�ky. Pozn�mka: Vr�cen� hodnota proto�e je r�zn� kombinace parametr� p�edan� serveru neodpov�d� obsahu bu�ky A1 nebo A3.

Tento obr�zek kompilov�n RTD server a Excel byl pomoc� verze komponenty run-time. Pro ��ely RTD lad�n� servery lze spustit z jazyka IDE.

Spu�t�n� v re�imu lad�n�:

1. Ukon�it aplikaci Microsoft Excel a p�epn�te do projektu v jazyka.
2. Stisknut�m kl�vesy F5 spu�t�n� komponenty. Pokud se zobraz� v dialogov�m okn� Vlastnosti projektu, klepn�te na tla��tko OK vyberte mo�nost v�choz� �ekat sou��sti b�t vytvo�en.
3. P�esv�d�te se, zda je zobrazen prom�nn�ch v jazyka. P�i zad�v�n� vzorce v bu�k�ch a jako bu�ky jsou aktualizov�ny prozkoumejte obsah prom�nn�ch v jazyka viz akce, kter� jsou upozorn�n�m r�zn� ud�losti.

Pozn�mka t�kaj�c� se ud�lost� DisconnectData

Zat�mco je aplikace Excel subscriber server RTD, aktivuje ud�lost DisconnectData Pokud ji� nepot�ebuje t�ma (nap��klad p�i odstran�n� nebo zru�te vzorec RTD v bu�ce). V�ak Excel nevyvol� DisconnectData na ka�d� t�ma pro RTD server p�i zav�en� se�itu nebo aplikace Excel ukon�ena; m�sto toho Excel vol� pouze ServerTerminate. P�i vytv��en� RTD server jste m�li k�d pro v�echny nezbytn� �i�t�n� t�mata nebo jin� objekty p�i ud�losti ServerTerminate.

(c) Microsoft Corporation 2001 v�echny rezervovan� pr�v. P��sp�vky Lenka B. Turner, Microsoft Corporation.

Dal�� informace z�sk�te v n�sleduj�c�m �l�nku znalostn� b�ze Microsoft Knowledge Base: