Why Form2 does not appear on the screen?

[Behzad]

Hi all,

I have made a MDI application.Let's say FrmSession and FrmProperties.I
want to create something like Photoshop.There are allways many
instances of FrmSession but at each there is only one instance of
FrmProperties.But the problem:

Every time the user makes a new session i create a new instance of
FrmSession in my method - let's say NewSession - and then i call
FrmProperties.Show() .

private void NewSession()
{
FrmSession newsession = new FrmSession();
myfrmproperties.Show(); // has been created it elesewhere & there
is only one insance of it
}

but the problem shows itself here.If the user closees the
FrmProperties; then the next time myfrmproperties.Show does not show
the form on the screen.I have checked if it has been nulled but debuger
says there is one intance.what is wrong with my code?

[Liewe]

Im not a guru, but I think hitting the cross does destroy the form.

I think you can solve it by adding an eventlistener to the formclosing event like:

this.Closing += new System.ComponentModel.CancelEventHandler(this.Form 2_Closing);

With a method like this:

private void Form2_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
e.Cancel = !close;
}

With close a boolean set to true when you really close your application (else it wont) and false if you dont really want to close it you still have to hide it somehow then :)

[Lloyd Dupont]

I guess that this line

myfrmproperies.Show(); // has been created it elesewhere & there

doesn't throw a NullReferenceException but, instead throw an
ObjectDisposedException, doesn't it?

override FormClosing() for it!

"Behzad" <Se*********@gmail.comwrote in message
news:11**********************@m73g2000cwd.googlegr oups.com...

Hi all,

I have made a MDI application.Let's say FrmSession and FrmProperties.I
want to create something like Photoshop.There are allways many
instances of FrmSession but at each there is only one instance of
FrmProperties.But the problem:

Every time the user makes a new session i create a new instance of
FrmSession in my method - let's say NewSession - and then i call
FrmProperties.Show() .

private void NewSession()
{
FrmSession newsession = new FrmSession();
myfrmproperties.Show(); // has been created it elesewhere & there
is only one insance of it
}

but the problem shows itself here.If the user closees the
FrmProperties; then the next time myfrmproperties.Show does not show
the form on the screen.I have checked if it has been nulled but debuger
says there is one intance.what is wrong with my code?

[Behzad]

Hi,

yes,what do you guess?

Thanks

[Lloyd Dupont]

hu?

"Behzad" <Se*********@gmail.comwrote in message
news:11**********************@h48g2000cwc.googlegr oups.com...

Hi,

yes,what do you guess?

Thanks

[Chris Dunaway]

Behzad wrote:

Hi,

yes,what do you guess?

Thanks

I think what Lloyd was trying to tell you is that when a form that was
opened with .Show is closed, it is automatically disposed.

You need to override the FormClosing event and instead of closing the
form, you need to .Hide the form. Then you will be able to show the
form again later.

Chris