[lazarus] More of a FPC question but... dynamic arrays
tonym at nlisc.com
Fri Oct 18 14:18:52 EDT 2002
On Sun, 2002-09-29 at 20:44, Andrew Johnson wrote:
> myarray : ^TObject;
> ...//do stuff
> reallocmem(myarray, 4*SizeOf(TObject));//allocmem to handle 4 objects
> myarray := thisobject;//set the 3 entry
> ...//do stuff.
> reallocmem(myarray, 0);//free memory
> you simply use reallocmem in place of setlength, and multiply the length by
> the sizeof the type it contains.. at one point I actually created wrappers
> arround this to make more like Delphi dynamic arrays..but its been awhile so
> I do not know if I still have it. essentially though you should be able to
> port a lot of code with ease. by doing some sort of wrappers.. etc.
Andrew (and others):
I've successfully been using the above to manage arrays of records, but
I finally tried to do objects this way and it won't work. Here's the
MyPrints: ^TChkTransaction; // array of transactions to print
Notice, I define a pointer and then attempt to make sure that the array
is zero length to begin with (actually I added this just because I was
testing why it crashed when I tried to set it the first time.)
It access violations before the writeln('Zeroed.') is executed.
At this point, I can't think of any reason it would cause a crash. All
I have is a pointer and I attempt to reallocate the memory for it...
It crashes on reallocmem regardless of the size I specify:
reallocmem(MyPrints,(2 * sizeof(TChkTransaction)))
both result in a crash. Am I doing something wrong?
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