Question

Do you know a way to trap, log, and re-raise exception in Delphi code?
A simple example:

procedure TForm3.Button1Click(Sender: TObject);
begin
  try
    raise Exception.Create('Bum');
  except
    on E: Exception do
    begin
      MyHandleException(E);
    end;
  end;
end;

procedure TForm3.MyHandleException(AException: Exception);
begin
  ShowMessage(AException.Message);
  LogThis(AException.Message);  
  // raise AException; - this will access violate
end;

So I need to re-raise it in the except block but I was wondering if there is a better way to write my own method to handle and (on specific conditions) to re-raise exceptions.

Answer 1

If you want to re-raise the exception only under certain conditions, write

procedure TForm3.Button1Click(Sender: TObject);
begin
  try
    raise Exception.Create('Bum');
  except
    on E: Exception do
    begin
      if MyHandleException(E) then
        raise;
    end;
  end;
end;

function TForm3.MyHandleException(AException: Exception): boolean;
begin
  ShowMessage(AException.Message);
  result := true/false;
end;