I have a C# class marked ComVisible that has a function that writes to a file. If the folder the file is supposed to be written to does not exist, it throws a System.IO.DirectoryNotFoundException. If I use throw; to raise it back to the C++ client, it doesn't get caught by any handler I know of except a generic (...) one. What is the type of the exception object that the handler will get?
Here is the client method:
void CRXReport::Export(CCOMString Destination)
{
CWaitCursor Wait;
// m_Report->Export("c:/misc/report2.pdf");
CCOMString message;
message << _T("Trying to export a report to ") << Destination;
AfxMessageBox(message);
if ( m_Report != NULL )
{
try
{
m_Report->Export(Destination.AllocSysString());
}
catch (CException& ex)
{
AfxMessageBox(_T("Failed to export the report; caught a CException reference."));
}
catch (CException* pEx)
{
AfxMessageBox(_T("Failed to export the report; caught a CException pointer."));
}
catch (_com_error* e)
{
AfxMessageBox(_T("Failed to export the report; caught a _com_error reference."));
}
catch (...)
{
AfxMessageBox(_T("Failed to export the report; caught something else."));
}
}
}
And, although I don't think it matters, here's the server method:
public void Export(string destination)
{
LogOnToTables();
try
{
_report.ExportToDisk(ExportFormatType.PortableDocFormat, destination);
}
catch (Exception ex)
{
MessageBox.Show("Failed to export report: " + ex.Message);
throw;
}
}
The first comment contains the answer. I needed to catch a _com_error reference, not a pointer.