Is there a way to have the close window button (X) call a method before actually closing the window?

Question

In a windows form project in C#/.net/Visual Studio 2010, if someone hits the close window button, I want to disable some other things in the program as a consequence. Is there a method call for hitting "X" that I can extend?

Answer 1

Just register a handler on the FormClosed event.

Answer 2

Your window class publishes two events for this purpose:

Closing allows you to cancel the close if it's inappropriate

Closed allows you to react on close.

Answer 3

The two events that you should use are FormClosing and FormClosed.

In the .Net Framework verion 2.0 these events replaced the obsolete Closing and Closed events.

The reason for the new events was that the old ones were not raised when the Application.Exit method was called.

An example of the usage of the FormClosing event is below:

public Form1()
{
    InitializeComponent();
    this.FormClosing += Form1_FormClosing;
}

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    DialogResult result = MessageBox.Show("Really close this form?", string.Empty, MessageBoxButtons.YesNo);

    if (result == DialogResult.No)
    {
        e.Cancel = true;
    }
}

That code simply asks the user if they want to close the form, and if No is selected, it then cancels the event. You can put any logic you require in the event handler.

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The MSDN article on Form.Closing is here and includes references about why the event was made obsolete. The reference for Form.FormClosing is here