Solved

Saving a variant type with a stream

Posted on 2000-04-14
3
830 Views
Last Modified: 2010-04-04
var
  VarArr: Variant;
  gh:^widestring;
begin
  VarArr:=VarArrayCreate([0,1],varVariant);
  VarArr:=Table2['Alpha;Graphic'];
 
  label1.caption:=inttostr(vartype(VarArr[1]));
 
My question is I need to save the image data through a variant array i cant use anything else. The problem is the variant array returns a reference to a widestring(that is what the label1 is telling us)how do i manage to assign the reference to a pointer or something so i can get the data to save to a stream. What i want to achieve is something like this but it does not work   gh:=pointer(vararr[1]);
0
Comment
Question by:flooder
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 10

Accepted Solution

by:
Lischke earned 100 total points
ID: 2716163
Hi Flooder,

if I understand you correctly then you just want to save the widestring returned by VarArr[1]? Well, this is somewhat easy to do:

var
  S: WideString;

begin
  S := VarArr[1];
  Stream.WriteBuffer(PWideChar(S)^, 2 * Length(S));
end;

To retrieve it later you can also write the length of the string just before the string itself:

var
  Size: Cardinal;

begin
  S := VarArr[1];
  Size := Length(S);
  Stream.WriteBuffer(Size, SizeOf(Size));
  Stream.WriteBuffer(PWideChar(S)^, 2 * Size);
end;


Ciao, Mike
0
 

Expert Comment

by:jonnyfive
ID: 2716228
Hi flooder...

as I have seen in your other posting, you are looking for something like this:

procedure SaveVariant(AnyVar: Variant; Filename : String);
function LoadVariant(Filename : String): Variant;

And, of course, it should save everything in the variant, including any arrays in it. Well, sounds like an intresting pet project :-] Well, I might have some time this weekend and see if I can do something like that (should be possible :-])...

Cya, Jonny...
0
 
LVL 1

Author Comment

by:flooder
ID: 2750486
Thanks for the help.
The other question still runs.
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
Introduction Raise your hands if you were as upset with FireMonkey as I was when I discovered that there was no TListview.  I use TListView in almost all of my applications I've written, and I was not going to compromise by resorting to TStringGrid…
In an interesting question (https://www.experts-exchange.com/questions/29008360/) here at Experts Exchange, a member asked how to split a single image into multiple images. The primary usage for this is to place many photographs on a flatbed scanner…

738 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question