Disabling top-level menu item does not disable children, in spite of what MSDN says?

Question

According to http://msdn.microsoft.com/en-us/library/aa984351%28VS.71%29.aspx

Disabling the first or toplevel menu item in a menu (for example, the "File" menu item in a traditional File menu) disables all the menu items contained within the menu. Likewise, disabling a menu item that has submenu items disables the submenu items.

According to http://msdn.microsoft.com/en-us/library/ms171655.aspx

Disabling the first or top-level menu item in a menu disables all the menu items contained within the menu. Likewise, disabling a menu item that has submenu items disables the submenu items.

However, if I create a new Windows Forms project and add the following code, I can still use the shortcut key to access the Child menu item that, according to MSDN, should be disabled.

public Form1()
{
    InitializeComponent();

    // Main menu
    MenuStrip mainMenu = new MenuStrip();
    this.Controls.Add(mainMenu);

    // Top Level menu
    ToolStripMenuItem topLevelMenuItem = new ToolStripMenuItem("&Top Level");
    mainMenu.Items.Add(topLevelMenuItem);

    // Child menu item
    ToolStripMenuItem childMenuItem = new ToolStripMenuItem("&Child...", null, (o, e) => MessageBox.Show("Doing something."));
    childMenuItem.ShortcutKeys = Keys.Control | Keys.C;
    childMenuItem.ShortcutKeyDisplayString = "Ctrl + C";
    topLevelMenuItem.DropDownItems.Add(childMenuItem);

    // Menu item to toggle the Top Level menu's Enabled property
    mainMenu.Items.Add(new ToolStripMenuItem("Toggle Enable for Top Level menu", null, (o, e) =>
    {
        topLevelMenuItem.Enabled = !topLevelMenuItem.Enabled;
        MessageBox.Show("topLevelMenuItem.Enabled = " + topLevelMenuItem.Enabled + Environment.NewLine + "childMenuItem.Enabled = " + childMenuItem.Enabled);
    }));
}

I can see that childMenuItem.Enabled is not changing at all, while topLevelMenuItem.Enabled does.

Sure, I could use a for loop to disable all menu items under the Top Level menu, or even disable just the Child menu item, but according to MSDN I shouldn't have to. What's the deal? Am I missing something, misinterpreting something, or is MSDN just wrong?

Answer 1

It is a bug. There are lots of bugs in the ToolStripItem classes, they were not fixed when the time was right (some time after the .NET 2.0 release), now it is too late. Posting these bugs to the Connect feedback site isn't useful, they'll just tell you to visit the MSDN forums to find a workaround. I think you already got one. Fwiw, here's one that matches your case.