通过传递参数从另一个事件方法中调用一个事件方法

Question

I am trying to call one EventHandler method from another. For example, I would like to link Logout button with form exit, so I have this code:

private void FormMain_FormClosing(object sender, FormClosingEventArgs e)
{
    if (MessageBox.Show("Bla, bla?", "Logout", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning) == DialogResult.OK)
    {
        e.Cancel = false;
    }
    else
    {
        e.Cancel = true;
    }
}

and I want to call it from this event:

private void btnLogOut_Click(object sender, EventArgs e)
{            
    FormMain_FormClosing(null, 'not sure what goes here');
}

Answer 1

Try this:

private void btnLogOut_Click(object sender, EventArgs e)
{            
    FormMain_FormClosing(null, null);
}

or

private void button1_Click(object sender, EventArgs e)
{
    Form1_FormClosing(
        null, 
        new FormClosingEventArgs(CloseReason.UserClosing, false));
}

Even if my answer cover how to link event handlers part, this particular solution leads you to a problem: form won't close clicking button.
Correct solution is

private void button1_Click(object sender, EventArgs e)
{
    Close();
}

Answer 2

Handling the event and asking for confirmation are seperate things:

private static bool UserConfirmedToLogout() 
{
    return MessageBox.Show("Bla, bla?", "Logout", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning) == DialogResult.OK;
}

private void FormMain_FormClosing(object sender, FormClosingEventArgs e)
{
    e.Cancel = !UserConfirmedToLogout();
}

private void btnLogOut_Click(object sender, EventArgs e)
{            
    Close();
}

When Close() is called, the FormClosing event is fired too.