Newbie Question:- Error destorying form dynamically created 1

[Jasonic]

I dynamically create a connection form with several components on it

3 x TLabel's
2 x TComobBox's
1 x TEdit
2 x TButton's

1 Button processes the connection
the other button cancels the connection and closes the form

with only two buttons on the form everything works fine as soon as I add any other components an exception error occurs.

I create each component as Create(Tform) NB. Tform is the dynamic form.

I also set the parent to TForm.

My Cancel button has the following code :-

GetParentForm(Sender as TControl).Destroy;

Any Ideas
or more information required

thanks in advance
Jason Jason Thomas
AssetCenter Consultant

http://www.corviz.com

 

[Jasonic]

Sorry

the exception occurs when clicking the cancel button Jason Thomas
AssetCenter Consultant

http://www.corviz.com

 

[Kocky]

The way you free your form is not correct. You are calling free from within the form. This is not possible. A form can only be freed by another form or object or its parent.

So, There is a function where you create the form dynamicly.
Let's say it's form1. From within form1 you create the dynamic form fom2. Your function should look like this:

procedure CreateADynamicForm(Sender: TObject)
var
form2: TForm2;
begin
form2 := TForm2.Create(Application);
try
form2.ShowModal;
finally
form2.Free;
end;
end;

The form form2 is created in form1 and freed by form1.
This is the correct way of creating and freeing a form.

 

[Jasonic]

Thanks for the reply, but if I have this form with a cancel button on it, how do I close the form once I have clicked the cancel button? Jason Thomas
AssetCenter Consultant

http://www.corviz.com

 

[Stretchwickster]

I normally use the following:

Close;

Clive

http://www.kucu.co.uk

Ex nihilo, nihil fit (Out of nothing, nothing comes)

 

[Jasonic]

Clive

Thanks for the obvious, but I had tried that with just close, and it closes the whole application.

I have just tried it with
GetParentForm(Sender as TControl).close;
and seems to work a treat

Thanks for the pointer Jason Thomas
AssetCenter Consultant

http://www.corviz.com

 

[Kocky]

If you called the form with:

form2.showmodal

then you can set the cancel's buttons modalresult property.
If you set it to mrCancel than the form will be closed automaticly.

If you called it with:

form2.show

then you have to close the form by calling form2.close.

Remind that closing a form doesn't mean that it is freed. After you closed it you have to free it with form2.free if it has been created dynamicly !

 

[Stretchwickster]

I just checked what I have used in the past to close forms (that aren't the main form). Here is what I have successfully used in the past:

ModalResult := mrCancel;

Clive

http://www.kucu.co.uk

Ex nihilo, nihil fit (Out of nothing, nothing comes)

 

[Stretchwickster]

Sorry Kocky - I think we double-posted! ;-) Clive

http://www.kucu.co.uk

Ex nihilo, nihil fit (Out of nothing, nothing comes)

 

[Kocky]

No prob