public bool TryGetValue(out object value)
{
// We need to be careful when this is called from an array formula.
// In the 'completed' case we actually still have to call xlfRtd, then only skip if for the next (single-cell calller) call.
// That gives us a proper Disconnect...
ExcelReference caller = XlCall.Excel(XlCall.xlfCaller) as ExcelReference;
bool isCallerArray = caller != null &&
(caller.RowFirst != caller.RowLast ||
caller.ColumnFirst != caller.ColumnLast);
if (_currentObserver == null || isCallerArray || !IsCompleted())
{
// NOTE: At this point the SynchronizationManager must be registered!
if (!SynchronizationManager.IsInstalled)
{
Debug.Print("SynchronizationManager not registered!");
throw new InvalidOperationException("SynchronizationManager must be registered for async and observable support. Call ExcelAsyncUtil.Initialize() in an IExcelAddIn.AutoOpen() handler.");
}
// Ensure that Excel-DNA knows about the RTD Server, since it would not have been registered when loading
ExcelObserverRtdServer.EnsureRtdServerRegistered();
// Refresh RTD call
// NOTE: First time this will result in a call to ConnectData, which will call Subscribe and set the _currentObserver
// For the first array-group call, this returns null (due to xlUncalced error),
// but Excel will call us again... (I hope).
if (!RtdRegistration.TryRTD(out value, _observerRtdServerProgId, null, _id))
{
// This is the special case...
// We return false - to the state creation function that indicates the state should not be saved.
value = ExcelError.ExcelErrorNA;
return(false);
}
}
else if (_currentObserver != null && IsCompleted())
{
// Special call for the Excel 2010 bug helper to indicate we are not refreshing (due to completion)
if (ExcelRtd2010BugHelper.ExcelVersionHasRtdBug)
{
ExcelRtd2010BugHelper.RecordRtdComplete(_observerRtdServerProgId, _id);
}
}
// No assumptions about previous state here - could have re-entered this class
// We use #N/A as the 'busy' indicator, as RTD does normally.
// Add-in creator can remap the 'busy' result in the UDF or another wrapper.
if (_currentObserver == null)
{
value = ExcelError.ExcelErrorNA;
return(true);
}
// Subsequent calls get value from Observer
value = _currentObserver.Value;
return(true);
}
// Forwarded from XlCall
// Loads the RTD server with temporary ProgId.
// CAUTION: Might fail when called from array formula (the first call in every array-group fails).
// When it fails, the xlfRtd call returns xlReturnUncalced.
// In that case, this function returns null, and does not keep a reference to the created server object.
// The next call should then succeed (though a new server object will be created).
public static bool TryRTD(out object result, string progId, string server, params string[] topics)
{
Debug.Print("### RtdRegistration.RTD " + progId);
// Check if this is any of our business.
Type rtdServerType;
if (!string.IsNullOrEmpty(server) || !registeredRtdServerTypes.TryGetValue(progId, out rtdServerType))
{
// Just pass on to Excel.
return(TryCallRTD(out result, progId, null, topics));
}
// TODO: Check that ExcelRtdServer with stable ProgId case also works right here -
// might need to add to loadedRtdServers somehow
// Check if already loaded.
string loadedProgId;
if (loadedRtdServers.TryGetValue(progId, out loadedProgId))
{
if (ExcelRtd2010BugHelper.ExcelVersionHasRtdBug && rtdServerType.IsSubclassOf(typeof(ExcelRtdServer)))
{
ExcelRtd2010BugHelper.RecordRtdCall(progId, topics);
}
// Call Excel using the synthetic RtdSrv_xxx (or actual from attribute) ProgId
return(TryCallRTD(out result, loadedProgId, null, topics));
}
// Not loaded already - need to get the Rtd server loaded
// TODO: Need to reconsider registration here.....
// Sometimes need stable ProgIds.
object rtdServer;
if (ExcelRtd2010BugHelper.ExcelVersionHasRtdBug && rtdServerType.IsSubclassOf(typeof(ExcelRtdServer)))
{
Debug.Print("### Creating Wrapper " + progId);
rtdServer = new ExcelRtd2010BugHelper(progId, rtdServerType);
}
else
{
using (XlCall.Suspend())
{
rtdServer = Activator.CreateInstance(rtdServerType);
}
ExcelRtdServer excelRtdServer = rtdServer as ExcelRtdServer;
if (excelRtdServer != null)
{
// Set ProgId so that it can be 'unregistered' (removed from loadedRtdServers) when the RTD server terminates.
excelRtdServer.RegisteredProgId = progId;
}
else
{
// Make a wrapper if we are not an ExcelRtdServer
// (ExcelRtdServer implements exception-handling and XLCall supension itself)
rtdServer = new RtdServerWrapper(rtdServer, progId);
}
}
// We pick a new Guid as ClassId for this add-in...
CLSID clsId = Guid.NewGuid();
// ... (bad idea - this will cause Excel to try to load this RTD server while it is not registered.)
// Guid typeGuid = GuidUtilit.CreateGuid(..., DnaLibrary.XllPath + ":" + rtdServerType.FullName);
// or something based on ExcelDnaUtil.XllGuid
// string progIdRegistered = "RtdSrv_" + typeGuid.ToString("N");
// by making a fresh progId, we are sure Excel will try to load when we are ready.
// Change from RtdSrv.xxx to RtdSrv_xxx to avoid McAfee bug that blocks registry writes with a "." anywhere
string progIdRegistered = "RtdSrv_" + clsId.ToString("N");
Debug.Print("RTD - Using ProgId: {0} for type: {1}", progIdRegistered, rtdServerType.FullName);
try
{
using (new SingletonClassFactoryRegistration(rtdServer, clsId))
using (new ProgIdRegistration(progIdRegistered, clsId))
using (new ClsIdRegistration(clsId, progIdRegistered))
{
Debug.Print("### About to call TryCallRTD " + progId);
if (TryCallRTD(out result, progIdRegistered, null, topics))
{
// Mark as loaded - ServerTerminate in the wrapper will remove.
loadedRtdServers[progId] = progIdRegistered;
Debug.Print("### Added to loadedRtdServers " + progId);
return(true);
}
return(false);
}
}
catch (UnauthorizedAccessException secex)
{
Logger.RtdServer.Error("The RTD server of type {0} required by add-in {1} could not be registered.\r\nThis may be due to restricted permissions on the user's HKCU\\Software\\Classes key.\r\nError message: {2}", rtdServerType.FullName, DnaLibrary.CurrentLibrary.Name, secex.Message);
result = ExcelErrorUtil.ToComError(ExcelError.ExcelErrorValue);
// Return true to have the #VALUE stick, just as it was before the array-call refactoring
return(true);
}
catch (Exception ex)
{
Logger.RtdServer.Error("The RTD server of type {0} required by add-in {1} could not be registered.\r\nThis is an unexpected error.\r\nError message: {2}", rtdServerType.FullName, DnaLibrary.CurrentLibrary.Name, ex.Message);
Debug.Print("RtdRegistration.RTD exception: " + ex.ToString());
result = ExcelErrorUtil.ToComError(ExcelError.ExcelErrorValue);
// Return true to have the #VALUE stick, just as it was before the array-call refactoring
return(true);
}
}
// Forwarded from XlCall
// Loads the RTD server with temporary ProgId.
public static object RTD(string progId, string server, params string[] topics)
{
Debug.Print("### RtdRegistration.RTD " + progId);
// Check if this is any of our business.
Type rtdServerType;
if (!string.IsNullOrEmpty(server) || !registeredRtdServerTypes.TryGetValue(progId, out rtdServerType))
{
// Just pass on to Excel.
return CallRTD(progId, null, topics);
}
// TODO: Check that ExcelRtdServer with stable ProgId case also works right here -
// might need to add to loadedRtdServers somehow
// Check if already loaded.
string loadedProgId;
if (loadedRtdServers.TryGetValue(progId, out loadedProgId))
{
if (ExcelRtd2010BugHelper.ExcelVersionHasRtdBug && rtdServerType.IsSubclassOf(typeof(ExcelRtdServer)))
{
ExcelRtd2010BugHelper.RecordRtdCall(progId, topics);
}
// Call Excel using the synthetic RtdSrv.xxx (or actual from attribute) ProgId
return CallRTD(loadedProgId, null, topics);
}
// Not loaded already - need to get the Rtd server loaded
// TODO: Need to reconsider registration here.....
// Sometimes need stable ProgIds.
object rtdServer;
if (ExcelRtd2010BugHelper.ExcelVersionHasRtdBug && rtdServerType.IsSubclassOf(typeof(ExcelRtdServer)))
{
Debug.Print("### Creating Wrapper " + progId);
rtdServer = new ExcelRtd2010BugHelper(progId, rtdServerType);
}
else
{
using (XlCall.Suspend())
{
rtdServer = Activator.CreateInstance(rtdServerType);
}
ExcelRtdServer excelRtdServer = rtdServer as ExcelRtdServer;
if (excelRtdServer != null)
{
// Set ProgId so that it can be 'unregistered' (removed from loadedRtdServers) when the RTD server terminates.
excelRtdServer.RegisteredProgId = progId;
}
else
{
// Make a wrapper if we are not an ExcelRtdServer
// (ExcelRtdServer implements exception-handling and XLCall supension itself)
rtdServer = new RtdServerWrapper(rtdServer, progId);
}
}
// We pick a new Guid as ClassId for this add-in...
CLSID clsId = Guid.NewGuid();
// ... (bad idea - this will cause Excel to try to load this RTD server while it is not registered.)
// Guid typeGuid = GuidUtilit.CreateGuid(..., DnaLibrary.XllPath + ":" + rtdServerType.FullName);
// or something based on ExcelDnaUtil.XllGuid
// string progIdRegistered = "RtdSrv." + typeGuid.ToString("N");
// by making a fresh progId, we are sure Excel will try to load when we are ready.
string progIdRegistered = "RtdSrv." + clsId.ToString("N");
Debug.Print("RTD - Using ProgId: {0} for type: {1}", progIdRegistered, rtdServerType.FullName);
try
{
using (new SingletonClassFactoryRegistration(rtdServer, clsId))
using (new ProgIdRegistration(progIdRegistered, clsId))
using (new ClsIdRegistration(clsId, progIdRegistered))
{
object result;
Debug.Print("### About to call TryCallRTD " + progId);
if (TryCallRTD(out result, progIdRegistered, null, topics))
{
// Mark as loaded - ServerTerminate in the wrapper will remove.
loadedRtdServers[progId] = progIdRegistered;
Debug.Print("### Added to loadedRtdServers " + progId);
}
return result;
}
}
catch (UnauthorizedAccessException secex)
{
Logging.LogDisplay.WriteLine("The RTD server of type {0} required by add-in {1} could not be registered.\r\nThis may be due to restricted permissions on the user's HKCU\\Software\\Classes key.\r\nError message: {2}", rtdServerType.FullName, DnaLibrary.CurrentLibrary.Name, secex.Message );
return ExcelErrorUtil.ToComError(ExcelError.ExcelErrorValue);
}
catch (Exception ex)
{
Logging.LogDisplay.WriteLine("The RTD server of type {0} required by add-in {1} could not be registered.\r\nThis is an unexpected error.\r\nError message: {2}", rtdServerType.FullName, DnaLibrary.CurrentLibrary.Name, ex.Message);
Debug.Print("RtdRegistration.RTD exception: " + ex.ToString());
return ExcelErrorUtil.ToComError(ExcelError.ExcelErrorValue);
}
}
