This post is 10 years old, and I'm still now sure what the question is or which control it's talking about. Can you please be specific about which control(s) you are using and what button you are referring to? 

Hi Mike,

it's about the closed (x) menu on ultraexplorerbar side menu,  last time i stuck how to prevent user close it. () 

i have solved my problem on my last project time with do some set value action on property on ultraexplorer bar (cannot remember which part i did), so user will not able to close menu, only able to change state hide or auto hide.

if it has some guide note about it, it will be helpfull for us,

I'm still not sure what button you are referring to. The ExplorerBar has a number of different styles. The only thing I could find that even resembles a menu that closes are the flyouts in the OutlookNavigationPane style. But I don't think there's any way to prevent that from closing since it's essentially a context menu. 

Maybe you can post a screen shot of what you are referring to? 

Add on information,

the disable closed menu was setup on ultradockmanager1 with set false on ShowCloseButton.

but it will helpfull if there is a function available how to call back the closed explorerbar menus.

The button in your screen shot is a button on a DockManager pane. It's not part of the ExplorerBar. The ExplorerBar doesn't have a close button. 

To disable the close button, you would do something like this: 

var pane = this.ultraDockManager1.PaneFromControl(this.ultraExplorerBar1);
pane.Settings.AllowClose = Infragistics.Win.DefaultableBoolean.False;