Delphi: How do I save array to file?
Martin Rommel
there a quick and easy way or do I have to do some workaround like
converting it into a text file (and use .Lines.SaveToFile) or create an
object out of it?
I'd like to avoid using the DB unit (I have not looked into the whole
database business, and hope I don't have to).
Any hints appreciated.
\\\\ ////
C-@,@ J. Martin Rommel (rom...@hermes.bc.edu) @/@-o
"\ -/ \o /*
Steve Teixeira
>I have an array on my form which I like to save and load from disk. Is
>there a quick and easy way or do I have to do some workaround like
>converting it into a text file (and use .Lines.SaveToFile) or create an
>object out of it?
>I'd like to avoid using the DB unit (I have not looked into the whole
>database business, and hope I don't have to).
>Any hints appreciated.
>
How about something like this (this is off the top o' my head, so double check
it):
type
MyArray : array[1..127] of word;
procedure SaveArray(var A: MyArray);
var
S: TFileStream;
begin
S := TFileStream.Create('ARRAY.SAV', fmCreate);
try
S.Write(A, SizeOf(A));
finally
S.Free;
end;
end;
procedure LoadArray(var A: MyArray);
var
S: TFileStream;
begin
S := TFileStream.Create('ARRAY.SAV', fmOpenRead);
try
S.Read(A, SizeOf(A));
finally
S.Free;
end;
end;
-Steve Teixeira
stei...@borland.com
Michael P. Hinds
>From: rom...@hermes.bc.edu (Martin Rommel)
>Subject: Delphi: How do I save array to file?
>Date: Wed, 12 Jul 1995 00:26:38 -0400
>I have an array on my form which I like to save and load from disk. Is
>there a quick and easy way or do I have to do some workaround like
>converting it into a text file (and use .Lines.SaveToFile) or create an
>object out of it?
>I'd like to avoid using the DB unit (I have not looked into the whole
>database business, and hope I don't have to).
>Any hints appreciated.
>\\\\ ////
>C-@,@ J. Martin Rommel (rom...@hermes.bc.edu) @/@-o
>"\ -/ \o /*
>
If you have defined a type for your array, it is a cinch:
program myProg;
type
myArray = ARRAY[1..20] OF MyRec;
var f : File of myArray;
A : MyArray;
begin
Assign(F, "filename.ext");
Reset(F);
{ and I believe I've read that assign and reset may have changed somewhat }
Read( F, A );
{ do stuff with A here }
Write( F, A );
Close( F );
end.
Simon Oke
mike...@mikehinds.seanet.com "Michael P. Hinds" writes:
>
> If you have defined a type for your array, it is a cinch:
>
[ stuff deleted ]...
OK, here's one that's been bugging me for a while.
I have a file which contains a contiguous block of (same-length)
records. I can only determine the number of records in the file
by opening it and reading a header from it. How can I read the records
in and access them as an array? Currently I have to use AllocMem
or whatever, and have a function which munges pointers to get the
address of the particular numbered record I want.
[BTW, this refers to the problem of reading the directory from
a DOOM .WAD...]
{ flame-proof trousers on }
Am I missing some obvious way of doing this, or is C superior in
this respect?
--
Simon Oke
Dag Sunde
If I'm not totally off the point, this should do it:
TYPE
TMyRec = Array[1..RecordSize] OF Byte;
VAR
f : File OF TMyRec;
MyRec : Array[1..NumRec] OF TMyRec;
n : WORD;
BEGIN
Assign( f, 'Jalla.WAD' );
ReSet( f, Length(MyRec) );
n := 0;
WHILE NOT EOF( f ) DO
BEGIN
Inc(n);
Read( f, MyRec[n] );
END; { while }
Close( f );
End;
Dag Sunde.
van...@wkuvx1.wku.edu
> In article <mikehinds....@mikehinds.seanet.com>
> mike...@mikehinds.seanet.com "Michael P. Hinds" writes:
>
>>
>> If you have defined a type for your array, it is a cinch:
>>
> [ stuff deleted ]...
>
> OK, here's one that's been bugging me for a while.
>
> I have a file which contains a contiguous block of (same-length)
> records. I can only determine the number of records in the file
> by opening it and reading a header from it. How can I read the records
> in and access them as an array? Currently I have to use AllocMem
> or whatever, and have a function which munges pointers to get the
> address of the particular numbered record I want.
>
> [BTW, this refers to the problem of reading the directory from
> a DOOM .WAD...]
>
> { flame-proof trousers on }
> Am I missing some obvious way of doing this, or is C superior in
> this respect?
>
> --
> Simon Oke
If you can assume that the total will be less thean 64k it's pretty
easy, otherwise you'll have to do a bit of tweaking such as having
array of pointers, etc... here goes.
type
fooRec = record
{ Your record def here }
end;
recArray = array[0..0] of fooRec;
ptrRecArray = ^recArray;
var
recs : ptrRecArray;
begin
:
{ Make sure range checking is off }
{ Read in # of records to allocate }
x := numRecs;
GetMem(recs, x * sizeof(fooRec));
BlockRead(file, recs^, x * sizeof(fooRec));
Now, you can access the records via recs[0]...recs[n]. This is the
simplist way I can find. Make sure you have range checking off during
access or you will get a runtime error.
Jay Cole