Re: Can't close my form. Close() isn't doing it.

[Daniel Hallmark <dgh@scott.net>]

On Sat, 3 Oct 1998, Aurora wrote:

> Now the pgm has no probs exitting if I close on a button event, but from
> FormCreate it won't work... I have my theories... I need solutions... :(


I don't know if this will work for you, but I ran into a similar problem.

First some background:
I write a lot of console CGI applications to process user input and 
return files/data/etc from my company's website.  The latest application 
had to create some graphs based on the numeric data I retrieved.  I tried 
to use dynamically allocated Teechart components, but at some point they 
were throwing an exception because they needed a window handle and 
didn't have one.

My next plan was to create a form with the charts on them.  I could then 
dynamically create the form and call its OnShow event from insde the 
console app.  In the form's OnShow event I built the charts and saved 
the images to disk.  Then I called Close() at the bottom of the OnShow 
event because I needed the form to close itself automatically without 
requiring any manual intervention.

The problem I ran into was that when the webserver ran the app, it would 
hang up.  After running the chart module thru the debugger I got an 
EInvalidOperation exception that said you couldn't modify the Visible
property (which Close() does) inside the OnShow event.

My final solution was to call form->Show and form->Close both from the 
external console part of the application instead of trying to have the 
form close itself.  I don't know if you can write some kind of a wrapper 
for your form, but maybe that would let you close the form and then 
terminate the app in a separate step.

Hope this helps :)
Daniel Hallmark

original method:
//inside console app
  TfrmChart *chart = new TfrmChart(0);
  chart->Show();
  delete chart;
//end of consol app
//inside TfrmChart::OnShow
  // build charts and save to disk
  Close(); // automatically close form -- this raises exception
//end of TfrmChart::OnShow

new method:
//inside console app
  TfrmChart *chart = new TfrmChart(0):
  chart->Show();    // if you need user interaction here ShowModal()
  chart->Close();
  delete chart;
//end console app