Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!mcnc!rti!bcw
From: bcw@rti.rti.org (Bruce Wright)
Newsgroups: comp.windows.ms
Subject: Re: Getting simple debug output
Summary: Debug messages
Message-ID: <4003@rtifs1.UUCP>
Date: 4 Aug 90 23:27:02 GMT
References: <1990Aug3.184951.5599@cs.umn.edu>
Organization: Research Triangle Institute, RTP, NC
Lines: 60

In article <1990Aug3.184951.5599@cs.umn.edu>, wytten@cs.umn.edu (Dale Wyttenbach) writes:
> I'm a experienced X11 programmer trying to write my first MSW
> program, and having a difficult time getting simple debug
> output from my program.  (I'm trying to avoid learning yet
> another debugger)
> 
> Right now I'm just opening a file called debug.txt and writing
> stuff into that, but I'd like to have a quickie function that
> pops up a dialog box with a message, sort of like this:
> 
> sprintf(buf,"a= %d, b=%d",a,b);
> debugwin(buf);
> 
> I would like to do this with a dialog box, but I don't know if you can
> pass the buf in since dialog boxes are defined in the .rc file.

The simplest way to get an error message into a dialog box is with
the MessageBox function - this puts up a small dialog box and a
message without requiring that you define the dialog box in the .rc
file.  Typical syntax is:

	MessageBox (hWnd, szBuffer, szAppName,
			MB_OK | MB_ICONEXCLAMATION);

(for example).  Note that you can get more pushbuttons by using 
somewhat different flags:  for example, MB_OKCANCEL has both an
OK and a Cancel pushbutton, and the function returns which button
was pushed.

One simple but useful function in many cases is one to check the 
range of a value and pop up a message box if it's out of range:

BOOL CheckRange (hWnd, iValue, iLow, iHigh, szMessage)
	HWND	hWnd;
	short	iValue, iLow, iHigh;
	char	*szMessage;
	{
	char	szBuffer [80];

	if ((iValue < iLow) || (iValue > iHigh))
		{
		wsprintf (szBuffer, szMessage, iValue);
		MessageBox (hWnd, szBuffer, szAppName,
				MB_OK | MB_ICONEXCLAMATION);
		return TRUE;
		}
	return FALSE;
	}

(This will only work on Windows 3.0 because wsprintf doesn't exist
in Windows 2.0, but you should be able to substitute sprintf - it
just takes more space.  szAppName is just a string with the name of 
the application and is put in the message box caption).

The main problem with this technique is that if you need a lot of
information (like writing out a lot of values in the message box or
you want to see previous error messages as well), it gets sort of 
cumbersome.

						Bruce C. Wright