Re: replacing unsigned char * with CString
 
Though it's not related to your problem, why don't rewrite the loop that 
way:
for (int i=0, j=0; i< radarMapSize; i+=63, j++) {
    for (int p = 0; p< 63 && p < radarMapSize - i;p++) {
        radarMapDataArray[j][p]=tempImage[p+i];
    }
}
This also works correctly for radarMapSize multiple of 63 (your original 
code doesn't handle that).
"Arlis Rose" <arlisATendevouraerospace.com> wrote in message 
news:useAkPSpGHA.4408@TK2MSFTNGP04.phx.gbl...
Okay, for some reason this one has me stumped.  I am trying to replace all 
of my char * (and unsigned char *) with CString's so to (hopefully) clean 
up the code and make it much easier to track down, fix, and avoid errors 
(such as not releasing memory, or not allocating enough memory, etc.).
My problem has arising when I try to read a lot of (essentially) random 
characters form a text file using the CFile::Read operator.  I am going to 
show both version of my code below (totally stripped down), hopefully 
someone can tell me how to use the CString properly in this case (or if I 
cannot use a CString what it is I should be using):
Example 1 (which works):
CFile imageFile;
unsigned char * tempImage = new unsigned char [15000];
imageFile.Open("USE.jpg", CFile::typeBinary | CFile::modeRead, NULL);
radarMapSize = imageFile.GetLength();
imageFile.Read(tempImage , radarMapSize);
imageFile.Close();
//Read data into the radarMapDataArray structure
for (int i=0; i<int(radarMapSize/63)+1; i++) {
   for (int p=i*63; p<i*63+63;p++) {
       int gh = (p%63);
       radarMapDataArray[i][p%63]=tempImage[p];
   }
}
(please ignore the fact I took out my error checking (around opening the 
file opening for example)...it is the 3rd last line that concerns me 
(radarMapDataArray[i]p%63]=tempImage[p];
When I rewrite this to use the CString it looks like so:
CFile imageFile;
CString imageString;
imageFile.Open("USE.jpg", CFile::typeBinary | CFile::modeRead, NULL);
radarMapSize = imageFile.GetLength();
imageFile.Read(tempImage.GetBuffer(radarMapSize), radarMapSize);
tempImage.ReleaseBuffer();
imageFile.Close();
//Read data into the radarMapDataArray structure
for (int i=0; i<int(radarMapSize/63)+1; i++) {
   for (int p=i*63; p<i*63+63;p++) {
       int gh = (p%63);
       radarMapDataArray[i][p%63]=tempImage.GetAt(p);
   }
}
and that (what I though was) equivalent line 
radarMapDataArray[i][p%63]=tempImage.GetAt(p); will now crash.  This is 
happening (I believe) because the file I am reading contains extended 
ASCII characters.  So of course that line crashes at different points 
depending on how many characters the CString actually contains (for 
example right now when I put in a breakpoint it only looks like the 
CString tempImage has 8 characters).
So I think I understand what is happening (the CString is only 8 
characters long so my call to GetAt() is trying to access memory that 
isn't allocated yet) but what I don't understand is how to make the two 
programs above equal.  I have tried putting a cast operation before my 
call to tempImage.GetBuffer(radarMapSize)  (I put (unsigned char *)) and 
this compiles and runs, but (naturally) doesn't do anything to fix the 
problem.
(Note - I also put a checkpoint in the first section of the code and my 
unsigned char * LOOKS to contain the same data as the CString would (only 
the 8 characters) however it's call using pointers [] doesn't crash 
whereas my GetAt() does :S
Can someone please point out to me what in the world I am doing wrong...I 
must be missing something??
Thanks,
Arlis T. Rose
  
  
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