/// <summary>
/// Adds a menu item to the form's system menu.
/// </summary>
/// <param name="title">The title of the menu to be displayed (or <c>null</c>).</param>
/// <param name="key">An application defined key to be used to identify the item when selected.</param>
/// <remarks>
/// <para>
/// Pass <paramref name="title" /> as <c>null</c> to append a menu separator instead of a menu item.
/// </para>
/// <note>
/// This works only for top-level forms. The application can
/// handle menu clicks by listening on the <see cref="SysMenuClick" /> event.
/// </note>
/// </remarks>
public void AddSysMenu(string title, string key)
{
var hSysMenu = WinApi.GetSystemMenu(this.Handle, false);
if (title == null)
{
WinApi.AppendMenu(hSysMenu, MenuFlags.MF_SEPARATOR, 0, string.Empty);
return;
}
WinApi.AppendMenu(hSysMenu, MenuFlags.MF_STRING, nextSysMenuID, title);
sysMenuMap.Add(nextSysMenuID, key);
nextSysMenuID++;
}