Solved

Simulation of Variant type property

Posted on 1997-08-23
4
218 Views
Last Modified: 2013-11-23
Do you know how to simulate a VARIANT Type on published property ?
0
Comment
Question by:dsam
[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
4 Comments
 
LVL 1

Expert Comment

by:sassas081597
ID: 1342302
via Pointer
0
 
LVL 3

Accepted Solution

by:
mirek071497 earned 200 total points
ID: 1342303
Yes i know how.

but full implementation is for you.
This is template only and with new button which have variant property. You must decide which variants you need (integer, string, float ...).
You must write own GetValue and SetValue to do conversion from and to string which will shown in Object Inspector.

unit Varcomp;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls;

type
  TTestVariant = class(TButton)
  private
    fVariant : Variant;
  protected {}
  public {}
  published {}
    property TestPropVariant : variant read fVariant write fVariant;
  end;

procedure Register;

implementation

uses
  DsgnIntf;

type
  TVarRecProperty = class(TPropertyEditor)
  public
    function AllEqual: Boolean; override;
    function GetValue: string; override;
    procedure SetValue(const Value: string); override;
  end;

procedure Register;
begin
  RegisterComponents('Samples', [TTestVariant]);
  RegisterPropertyEditor( TypeInfo(Variant), TComponent, '', TVarRecProperty );
end;

function TVarRecProperty.AllEqual: Boolean;
var
  I: Integer;
  V: Variant;
begin
  Result := False;
  if PropCount > 1 then
  begin
    V := GetVarValue;
    for I := 1 to PropCount - 1 do
      if GetVarValueAt(I) <> V then Exit;
  end;
  Result := True;
end;

function TVarRecProperty.GetValue: string;
var Vv : Variant;
begin
  Vv := GetVarValue;
  Result := '12.12';  { here you must change Variant Vv to string }
end;

procedure TVarRecProperty.SetValue(const Value: string);
var V : Variant;
begin
  Vv := 12.12; { here you must change String to Vv Variant Value }
  SetVarValue( Vv );
end;

end.
0
 
LVL 3

Expert Comment

by:mirek071497
ID: 1342304
Hi
What happened ? Any questions ?
0
 
LVL 3

Expert Comment

by:mirek071497
ID: 1342305
another man on holliday.
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

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

Introduction The parallel port is a very commonly known port, it was widely used to connect a printer to the PC, if you look at the back of your computer, for those who don't have newer computers, there will be a port with 25 pins and a small print…
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…
There's a multitude of different network monitoring solutions out there, and you're probably wondering what makes NetCrunch so special. It's completely agentless, but does let you create an agent, if you desire. It offers powerful scalability …
Michael from AdRem Software outlines event notifications and Automatic Corrective Actions in network monitoring. Automatic Corrective Actions are scripts, which can automatically run upon discovery of a certain undesirable condition in your network.…

719 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