Thanks for your replies, Jeff. Doh! I had forgotten that since I was declaring (char **) I had to do MemPtrNew twice, once for each dimension.
But now I'm getting the error that says I'm basically running out of space, or I didn't allocate enough space in my buffer. I'm just trying to allocate n rows of 3 chars (including the null char). My code is the same, except I've added the line within the loop: diffs[d] = (char *) MemPtrNew(3 * sizeof(char)); Then, I tried your 2nd suggestion, simply declaring a static array char diffs[MY_MAX_SIZE][10]; That gets farther than the other method, but crashes when actually drawing the list. I thought I had found older posts similar to this problem last week, but now I can't find them. But there seemed to be a frequently encountered problem when drawing a dynamically generated list.... --- In [EMAIL PROTECTED], "Jeff Wheeler" <[EMAIL PROTECTED]> wrote: > Your error isn't related to the lists at all, but rather to incorrect use of > pointers and memory allocations. Your memory allocation is wrong or > incomplete. You are allocating a block of memory and telling the compiler > that it will contain an array of pointers to other characters, but then you > access those pointers without initializing them. The value of these > pointers is garbage, so you generate an error. > > Try something like this: > > #define MY_MAX_SIZE 3 > > Char ** diffs = (Char **) MemPtrNew(level * sizeof(Char *)); > for (d=0; d<level; d++) > diffs[d] = (Char *) MemPtrNew(MY_MAX_SIZE * sizeof(Char)); > > ... > > // Free memory appropriately when done... > > Or, > > Char ** diffs = (Char **) MemPtrNew(level * sizeof(Char *)); > Char * buffer = (Char *) MemPtrNew(level * sizeof(Char) * MY_MAX_SIZE); > for (d=0; d<level; d++) > diffs[d] = &buffer[d * sizeof(Char) * MY_MAX_SIZE]; > > ... > > // Free memory appropriately when done. > > Or, just declare an array that is big enough for what you want. If the > scope of the variables is only this function and doesn't need to be global, > then the size is likely small enough to reasonably store it on the stack. > > Char diffs[MY_MAX_SIZE][10]; > > (Or it may be diffs[10][MY_MAX_SIZE] -- I always have to look it up.) > > Make sure you allocate memory for the NULL that will terminate the string. > Code above has not been compiled or debugged, but should serve for an > example. > > Jeff > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Brian > Preston > Sent: Friday, June 13, 2003 4:45 PM > To: Palm Developer Forum > Subject: bus error building dynamic list > > I'm trying to build my first dynamic list. 'Dynamic' > might be an exaggeration, I'm simply trying to build a > list of numbers 1 through x, where x's max value is > 10, and x is randomly determined. The error occurs at > the first StrCopy. What am I doing wrong? I'm also not > sure if I need 3 chars for each line instead of two, > to include the null terminator at the end of each > string. > > Here's the code: > > int level = GetRandom(10)+1; > int d=0; > char SBuf2[5]; > > char **diffs = (char **) MemPtrNew (level * 2 * > sizeof(char)); > > for (d; d < level; d++) { > > if ( d<9) { > StrCopy(diffs[d], " "); > StrIToA(SBuf2, d+1); > StrCat(diffs[d], SBuf2); > } else { > StrCopy(diffs[d], "10"); > } > > } > > LstSetListChoices(GetObjectPtr(StartDifficultyList), > diffs, level); > LstSetSelection(GetObjectPtr(StartDifficultyList), level-1); > __________________________________ Do you Yahoo!? SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
