?
Solved

redirecting exception to a log file

Posted on 1997-07-16
3
Medium Priority
?
152 Views
Last Modified: 2010-04-06
I have all my error messages set up as exceptions. How can i set it up so that any exceptions occuring are written to a log file as well as the screen. (D1).

Thanks.

Tom.
0
Comment
Question by:boardtc
  • 2
3 Comments
 
LVL 4

Accepted Solution

by:
erajoj earned 150 total points
ID: 1338969
Here is a very simple example of an exception logger in D1:

unit Main;

interface

uses
  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs, StdCtrls, Buttons, ExtCtrls, Menus;

type
  TMainForm = class(TForm)
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    procedure MyExceptionHandler(Sender: TObject; E: Exception);
  end;

var
  MainForm: TMainForm;

implementation

{$R *.DFM}

procedure TMainForm.MyExceptionHandler(Sender: TObject; E: Exception);
var
  LogFile: TextFile;
begin
  AssignFile(LogFile, 'log.txt');
  if not FileExists('log.txt')
  then ReWrite(LogFile)
  else Append(LogFile);
  Writeln(LogFile, DateTimeToStr(Now), ': ', E.Message);
  CloseFile(LogFile);
end;

procedure TMainForm.FormCreate(Sender: TObject);
begin
  Application.OnException := MyExceptionHandler;
end;

procedure TMainForm.Button1Click(Sender: TObject);
var
  x: Real;
begin
  try
    x := x/0;
  except
  end;
end;

end.

Hope this is what you need!

/// John

0
 
LVL 4

Expert Comment

by:erajoj
ID: 1338970
Hmm-hmmm!
I screwed up! To handle the exceptions this way you have
to re-raise the exception after "except":

  try
    x := x/0;
  except
    raise
  end;

Or simply exclude the try-blocks...!

Sorry!

/// John
0
 

Author Comment

by:boardtc
ID: 1338971
John,

Thanks. Simply a matter of assigning a procedure to the Application.OnException and then you can do as you want.

Cheers.

Tom.
0

Featured Post

Get expert help—faster!

Need expert help—fast? Use the Help Bell for personalized assistance getting answers to your important questions.

Question has a verified solution.

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

In this tutorial I will show you how to use the Windows Speech API in Delphi. I will only cover basic functions such as text to speech and controlling the speed of the speech. SAPI Installation First you need to install the SAPI type library, th…
Hello everybody This Article will show you how to validate number with TEdit control, What's the TEdit control? TEdit is a standard Windows edit control on a form, it allows to user to write, read and copy/paste single line of text. Usua…
The Relationships Diagram is a good way to get an overall view of what a database is keeping track of. It is also where relationships are defined. A relationship specifies how two tables connect to each other. As you build tables in Microsoft Ac…
This video tutorial shows you the steps to go through to set up what I believe to be the best email app on the android platform to read Exchange mail.  Get the app on your phone: The first step is to make sure you have the Samsung Email app on your …
Suggested Courses

616 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