// The call to LPenHelper will cause an AccessViolation after Excel starts shutting down.
// .NET40: If this library is recompiled to target .NET 4+, we need to add an attribute to indicate that this exception
// (which might indicate corrupted state) should be handled in our code.
// For now, we target .NET 2.0, and even when running under .NET 4.0 we'll see the exception and be able to handle is.
// See: http://msdn.microsoft.com/en-us/magazine/dd419661.aspx
// (Also for CheckExcelApiAvailable())
// [HandleProcessCorruptedStateExceptions]
static int CallPenHelper(int wCode, ref XlCall.FmlaInfo fmlaInfo)
{
try
{
// (If Excel is shutting down, we see an Access Violation here, reading at 0x00000018.)
return XlCall.LPenHelper(XlCall.xlGetFmlaInfo, ref fmlaInfo);
}
catch (AccessViolationException ave)
{
throw new InvalidOperationException("LPenHelper call failed. Excel is shutting down.", ave);
}
}
public XlCallException(XlCall.XlReturn xlReturn)
{
this.xlReturn = xlReturn;
}