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Author Topic: TRegIniFile raises exception  (Read 13591 times)

BjPascal

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TRegIniFile raises exception
« on: July 11, 2018, 03:11:24 pm »
using Lazarus 1.9.0 in Delphi-mode and FPC 3.1.1 on Win7 x64

When using TRegIniFile then the first Readinteger works ok.

reg:= TRegIniFile.Create('\Software\myName\myApp');
i:= reg.ReadInteger(SECT_SETTINGS, 'edRcvUdpPort', 0);
i:= reg.ReadInteger(SECT_SETTINGS, 'edRcvUdpPort', 0);

But the second identical Readinteger generates this
   "Project * raised exception class 'External: ?'"

The same with other read methods. It seems I can use a method only once.
Any idea why and how to fix it?

I imported it from Delphi and don't want to modify the source.


Trenatos

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Re: TRegIniFile raises exception
« Reply #1 on: July 11, 2018, 05:12:47 pm »
http://wiki.freepascal.org/Using_INI_Files

The wiki for FPC shows TINIFile.Create(); rather than TRegIniFile.Create();

BjPascal

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Re: TRegIniFile raises exception
« Reply #2 on: July 11, 2018, 06:56:19 pm »
I use Registry acces with the option to easily switch to ini files if needed.

Trenatos

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Re: TRegIniFile raises exception
« Reply #3 on: July 11, 2018, 07:27:17 pm »

BjPascal

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Re: TRegIniFile raises exception
« Reply #4 on: July 12, 2018, 01:25:37 am »
I now found the error:
each method-call closes the key. So a subsequent call returns with "handle is invalid".
I fixed regini.inc at the bottom:

procedure TRegIniFile.CloseSection;
begin
//  CloseKey(CurrentKey);
end;

and it now works fine!

Bart

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Re: TRegIniFile raises exception
« Reply #5 on: July 12, 2018, 06:44:53 pm »
Worsk fine (without your patch) for me (win32 fpc 3.04 and 3.1.1).

Bart

Thaddy

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Specialize a type, not a var.

Bart

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Re: TRegIniFile raises exception
« Reply #7 on: July 12, 2018, 08:20:22 pm »
Tested with fpc 3.0.4 win32 and win64 and win fpc trunk (r39352) win32:

Code: Pascal  [Select][+][-]
  1. program rtest;
  2.  
  3. {$apptype console}
  4. {$ifdef fpc}{$mode objfpc}{$endif}
  5.  
  6. uses
  7.   registry, sysutils;
  8.  
  9. var
  10.   RegIni: TRegIniFile;
  11.   WFileName: String;
  12.   i: Integer;
  13. begin
  14.   RegIni := TRegIniFile.Create(
  15.       'Software\MicroSoft\Windows\CurrentVersion\Explorer');
  16.   try
  17.     for i := 1 to 3 do
  18.     begin
  19.       WFileName := RegIni.ReadString ('Shell Folders', 'Desktop', 'Failure!');
  20.       writeln(format('Try %d: WFileName = "%s"',[i,WFileName]));
  21.     end;
  22.   finally
  23.     RegIni.Free;
  24.   end;
  25. end.

Outputs

Code: [Select]
C:\Users\Bart\LazarusProjecten\bugs\Console\regini>rtest
Try 1: WFileName = "C:\Users\Bart\Desktop"
Try 2: WFileName = "C:\Users\Bart\Desktop"
Try 3: WFileName = "C:\Users\Bart\Desktop"

Bart

BjPascal

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Re: TRegIniFile raises exception
« Reply #8 on: July 13, 2018, 10:25:27 am »
Yes Bart that works.

But not this, where the "Section"-name has been moved to the create path to keep subsequent calls of the same section simpler.
Code: Pascal  [Select][+][-]
  1. RegIni := TRegIniFile.Create('Software\MicroSoft\Windows\CurrentVersion\Explorer\Shell Folders');
  2.  for i := 1 to 3 do
  3.      WFileName := RegIni.ReadString ('', 'Desktop', 'Failure!');
  4.  

wp

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Re: TRegIniFile raises exception
« Reply #9 on: July 13, 2018, 10:45:20 am »
Yes Bart that works.

But not this, where the "Section"-name has been moved to the create path to keep subsequent calls of the same section simpler.
Code: Pascal  [Select][+][-]
  1. RegIni := TRegIniFile.Create('Software\MicroSoft\Windows\CurrentVersion\Explorer\Shell Folders');
  2.  for i := 1 to 3 do
  3.      WFileName := RegIni.ReadString ('', 'Desktop', 'Failure!');
  4.  
But RegIniFile still is an IniFile after all. Would you do the same with TIniFile?

Bart

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Re: TRegIniFile raises exception
« Reply #10 on: July 13, 2018, 02:48:31 pm »
But RegIniFile still is an IniFile after all. Would you do the same with TIniFile?

It may not be best practice, but it should not crash.
TRegIniFile is a derivative of TRegistry, not of TInifile b.t.w.
It should be perfectly OK to query register values multiple times.

B.t.w. I was unaware of the fact you could leave Section parameter empty.
Is that officially supported?

Bart
« Last Edit: July 13, 2018, 02:50:50 pm by Bart »

Bart

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Re: TRegIniFile raises exception
« Reply #11 on: July 13, 2018, 04:34:30 pm »
Even with Section parameter empty I still don't get a crash (but on second try reading fails).
Delphi (7) seems to allow that and consecutive reads are OK.

Bart

Bart

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Re: TRegIniFile raises exception
« Reply #12 on: July 13, 2018, 04:49:44 pm »
Reported as issue 33980.

Bart

wp

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Re: TRegIniFile raises exception
« Reply #13 on: July 13, 2018, 05:07:04 pm »
TRegIniFile is a derivative of TRegistry, not of TInifile b.t.w.
I do remember that in my Delphi days I had replaced TIniFile by TRegIniFile in order to easily store the settings to the registry without changing anything else. This must be the reason why I confused it.

BjPascal

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Re: TRegIniFile raises exception
« Reply #14 on: July 15, 2018, 10:33:40 am »
Bart,

I have been using the empty section from Delphi-5 to Berlin, simply because it is much clearer to have the registry tree defined in one single constant instead of breaking it up into two. And TRegini has been my favourite because it's a lot simpler to use than anything else.

I found another bug:
When using
TRegIniFile.Create('\Software\myName\myApp');

(with leading backslash) then all write operations will fail, because these always prepend another '\' to it.
The read functions don't have that issue.

Delphi treats both cases properly.
So you might add this to your issue report also.

 

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