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Form Events - Closing, Disposing - Removing from collections when closed

P: n/a

I have a ChatFormCollection class which holds a collection of the class
ChatForm which inherits from Form.
MainForm has an instance of ChatFormCollection.
When a ChatForm instance is created it is added to the ChatFormCollection of

This works fine, but I've always found the removing hard.
Because the form has to be removed from the collection when the user closes
the form, but not when he minimizes the form.

I tryed the following code

private void ChatForm_Closed(object sender, System.EventArgs e)

but apparently the form never gets removed from the collection
and when the following code is called again:

int index = this.chatForms.IndexOf((LmimUser)this.lstContacts. SelectedItem);

if(index < 0)
index = this.chatForms.Add(new
ChatForm(this,(LmimUser)this.lstContacts.SelectedI tem));


I get the following exception (while the form it is trying to access should
actually have been removed from the collection
and therefore a new form should have been added to the collection.)

An unhandled exception of type 'System.ObjectDisposedException' occurred in
Additional information: Cannot access a disposed object named "ChatForm"

Can someone help me with this?



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Jul 21 '05 #1
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