Mega Code Archive
TRegistry has a weird behaviour within Windows 2000
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Title: TRegistry has a weird behaviour within Windows 2000
Question: If you log in Windows 2000 as a Power User, you have to pay attention to a small "bug" (?) in TRegistry
Answer:
I'm still sorry for my english ;-)
I discovered a weird behaviour of the TRegistry object when I'm developing software on Windows 2000.
Follow these steps:
1) If you are the Administrator of the Windows 2000 system, create a new user as "Power user" (or "Standard user").
2) Log out and log in again as that power user. Probably you have to re-install Delphi, so I suggest to use the "Registry" setting during the setup, so it will create only the required links for Delphi (notice: you may also have to re-install every component).
3) Let's suppose you did the previous two steps: launch Delphi and place a Button on the form that appears after startup, and double click on the button.
4) Copy the following code and paste into the unit:
//------ Beginning of the Code ------------
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, Registry,
StdCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
var
Reg: TRegistry
begin
Reg:=TRegistry.Create;
with Reg do
begin
RootKey:=HKEY_CLASSES_ROOT;
OpenKey('\TestKey',true); // (1)
WriteString('Test String','Test Value');
CloseKey;
end;
Reg.Free;
end;
end.
//------ End of the Code ------------
When you are developing within Windows 98 the syntax of the line that I marked with (1) is correct: it means "Open the registry key 'TestKey' - if it doesn't exists then create it, else just open it".
In Windows 98 this code works, but in Windows 2000 (and a Power User logged in) you will get a "failed set data for..." error. This error means that something went wrong.
Let's go back to the code and replace only the line (1) with the following code:
//------ Beginning of the Code ------------
if KeyExists('\TestKey') then
OpenKey('\TestKey',false)
else
OpenKey('\TestKey',true);
//------ End of the Code ------------
Okay, I know: it's really a weird thing but this seems to be the only way to avoid that error.
What should I say? This little snippet does the job that the OpenKey function should do (as it does in Windows 98).
Bye.
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