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OnError in Delphi

Exists some way to determine and to control (aside from try) the error that causes that an application is cancelled?
Something similar to the OnError de Visual BASIC exists, I I am using Delphi 5.
Greetings Ruben
0
rbarzallo
Asked:
rbarzallo
2 Solutions
 
MotazCommented:
use try except:

try
  AssignFile(F, 'test.file');
  Reset(F);
  Writeln(F, 'test');
  CloseFile(F);
except
on e: exception do
  ShowMessage(E.Message);
end; // try

// Program execution will resume normally
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intheCommented:
hi,
another way if your trying to catch a particular exception you can use the application.onexception event:
many of the "e" exceptions are in sysutils and the db units.

  private
    { Private declarations }
procedure MyExceptionHandler(Sender: TObject; E :Exception);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}
procedure TForm1.MyExceptionHandler(Sender: TObject; E :Exception);
begin
  if E is EOutOfMemory then
   begin
   showmessage('EOutOfMemory');
   end
    else
   if E is EInOutError then
   begin
   showmessage('EInOutError');
   end
    else
   if E is EDivByZero then
   begin
   showmessage('EDivByZero');
   end
    else
   if E is EAbort then
   begin
   showmessage('EAbort');
   end;
//following is to to catch any other errors
   Application.showException( E);
  end;

procedure TForm1.FormCreate(Sender: TObject);
 begin
  Application.onException := MyExceptionHandler;
 end;

end.
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MadshiCommented:
You might also want to look at my exception handling package (free for non-commercial usage):

http://help.madshi.net/Data/madExcept.htm

Regards, Madshi.
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rbarzalloAuthor Commented:
Thanks for their aid, but really what I need are something that allows me to control the exceptions that appear within a task, I that I can place try..except in each place that I believe that it is going away to present/display a problem but it must have another solution.

Madshi,

what I understand or I am mistaken, its application madexcept does not report errors within tasks?




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MadshiCommented:
madExcept shows exceptions that occur in your program and that are NOT catched by "try..except" blocks. Normally in such a case you get a short box like "error blabla at address $12345678". With madExcept the box get much more detailed.
Furthermore you can register your own exception handlers, that e.g. don't show the box but instead send the exception to you via email or something like that.
Basically you can do something similar (I mean don't show the box, but send the exception via mail) without madExcept, too (by using Application.OnException), but madExcept catches some more exceptions, that doesn't run through Application.OnException. Furthermore with madExcept you have much more detailed exception information.

If I understand you correctly, you should either go with Application.OnException or with madExcept.RegisterExceptionHandler.

Regards, Madshi.
0
 
rbarzalloAuthor Commented:
The routine this very good and works correctly. The additional question is:
The program A main executes a task that is in another program B, since I can make so that program B, when error detects algun takes exception from program A.
Greetings Ruben
0
 
rbarzalloAuthor Commented:
The routine this very good and works correctly. The additional question is:
The program A main executes a task that is in another program B, since I can make so that program B, when error detects algun takes exception from program A.
Greetings Ruben
0
 
DragonSlayerCommented:
rbarzallo,
No comment has been added lately (808 days), so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area for this question:

RECOMMENDATION: split points between inthe http:#6197564 and madshi

Please leave any comments here within 7 days.

-- Please DO NOT accept this comment as an answer ! --

Thanks,

DragonSlayer
EE Cleanup Volunteer
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