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From: ksitze@nmsu.edu (Kevin Sitze)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Dialog Crash
Message-ID: <KSITZE.89May30122016@picuris.nmsu.edu>
Date: 30 May 89 18:20:16 GMT
References: <1415@ns.network.com>
Sender: news@nmsu.edu
Organization: NMSU Computer Science
Lines: 65

In article: <jmh@ns.network.com's message of 30 May 89 16:15:45 GMT>
Joel writes:
>In an application I am attempting to write, I have a dialog with one
>edittext item (item 2).  When the dialog is requested from the menu,
>the routine starts with:
>
>char strbuf[60];
>GetDItem(dialog, 2, handle);
>/* set the string at strbuf+1 to the desired display */
>[s]trbuf[0] = strlen(strbuf+1);
>SetIText(handle, strbuf);
>
>Then I enter a loop:
>
>do {
>	ModalDialog(dialog, &theItem);
>	if (theItem == 2) {
>		GetDItem(dialog, theItem, handle);
>		GetIText(handle, strbuf);
>		/* process input */
>	}
>} while (theItem != 1 && tehItem != exititem);

Your problem lies in an incorrect call to GetDItem as well as a bad
call to ModalDialog.  You're code should look like this: (Plus some
streamlining...) (Changed lines are marked with a '>')

>#define NIL (0L)
char strbuf[60];
>GetDItem(dialog, 2, &itmKind, &myHandle, &myRect);
/* set the string at strbuf+1 to the desired display */
strbuf[0] = strlen(strbuf+1);
SetIText(myHandle, strbuf);
do {
>	ModalDialog(NIL, &theItem);	/*
	if (theItem == 2) {
>		/* the call to GetDItem is not needed here, already	*/
>		/* have info that was needed, namely myHandle.		*/
>		GetIText(myHandle, strbuf);
		/* process input */
	}
} while (theItem != 1 && theItem != exitite);

I changed your 'handle' variable to 'myHandle' because I program in
LSP (which is not case-sensitive) and I don't like seeing
'duplications' between types and variables. (No particular reason...)

ModalDialog assumes that the first parameter being passed is a pointer
to a filter _function_, NOT a dialog (as you seemed to have done here).

This will most probably cause an address error (Error #02 in the
SysError dialog box) when you do anything at all with that dialog.

I'm surprised that LSC allowed you to compile the above code because
ususally it does type-checking on ROM calls (they ARE after all,
PASCAL calls)  Rich, any ideas?

				-Kelesi
--
+--------------------------------------------------------------------+
| From the Macintosh of: Kevin L. Sitze. This is ME: ksitze@NMSU.edu |
+------------------------------------------------------+-------------+
| The difference between intelligence and stupidity is |   Is this   |
| that intelligence has a limit.          -- anonymous |   better?   |
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