Don't show context menu if nothing is selected

Question

I like to have a context menu only show up if an item is actually selected in a listbox in a winforms c# application.

Currently, I am able to select an item if it is right clicked properly, and I can disable the right click menu if nothing is selected, however, I don't want the menu to even show up.

how can this be accomplished?

private void genPassMenu_Opening(object sender, CancelEventArgs e)
    {
        genPassMenu.Enabled = lstPasswords.SelectedIndex > 0;
        genPassMenu.Visible = lstPasswords.SelectedIndex > 0;

    }

I tried both of those situations on their own, and it only works for enabled.
Perhaps Opening isn't the correct event to choose?
Tx

Answer 1

Try this:

private void genPassMenu_Opening(object sender, CancelEventArgs e)
{
    //if (lstPasswords.SelectedIndex == -1) e.Cancel = true;
    e.Cancel = (lstPasswords.SelectedIndex == -1);
}

Answer 2

Easy,

    private void genPassMenu_Opening(object sender, CancelEventArgs e) 
    { 
        e.Cancel = (lstPasswords.SelectedIndex == 0); 

    }