Re: Exception handling?
You should avoid these obsolete macros. They were created before the
C++ compiler correctly implemented (or implemented at all) the C++
exception syntax.
****
Use try (lower case)
{
ar >> FileID;
if (FileID != 0x1234ABCD)
****
Ok, noted, you gave me so much to work with I will have to get
back with you on most of this Actually what I am most concerned
with right now is learning all of what you just gave me.
I stepped thru my doc return code again and it appears that is not
currently doing what I had hoped. I realize if I click SAVE it is going to
save whatever new document data in currently in the members. What I
was hoping for was that the exception code would void out the current
lpszFileName doc variable so that at least when I click save it would
prompt me for a filename instead of just overwriting what is in the
lpszFileName.
Why is this a hardwired literal? Why did you not do
const DWORD CURRENT_FILEID = 0x1234ABCD;
?
****
Ugh maybe because I am a dummy and have not learned any better?
{ // FileID mismatch
AfxThrowUserException( );
****
I would have done
throw new CWrongFileIDException(FileID)
where I would have defined a specific exception that did exactly what
I wanted
class CWrongFileIDException : public CException {
public:
DWORD GetFileID() { return fid; }
CWrongFileIDException(DWORD fileid) { fid = fileid; }
protected:
DWORD fid;
};
You should not "hijack" some other exception to mean other than what
precisely happened!
****
Ok give me some time to work with this.
****
Query: why are you putting an English language message in SOURCE code?
That's what STRINGTABLEs are for!
This was only just for "me" to see if / when it was actually called.
Query: Why did you declare the variable E so far from where it is used?
It should be written, if you want to keep the really bad idea of English strings,
CString E = _T("...");
that is, you should never declare a variable in a scope wider than it needs to exist!
The stuff about where to declare the vars I really just have not gotten that far yet,
but appreciate it and will try to incorporate it into my current attempt to learn
exceptions.
And for that matter, why did you have to declare a CString for AfxMessageBox?
Well for the one I did not have to, but I got into the CString originally in order
to copy the strings together
e->GetErrorMessage(szErrMsg, 255);
E = _T("RB from inside AND_CATCH\n");
E += szErrMsg;
// Again the English is just for me to "see" when it was called.
.....
You should also do
e->Delete();
to handle the case where the exception was thrown with 'new'
****
Ok I will have to digest these new items and look in some other docs for this.
Thanks.