Hi Matt,
Thanks for your interest in Syncfusion products,
Closing a window from the DockingManager sets the Windows dockVisibility to false, so that the window can be displayed again,
if you need to release the control from the DockingManager you can use SetEnableDockgin method of the docking manager as follows,
// removes and releases the control from the DockingMangaer
this.dockingManager1.SetEnableDocking(this.GroupBar1, false);
// releases the custom caption buttons that are used
BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.NonPublic;
FieldInfo fieldInfo = dockingManager1.GetType().GetField("htCustomCaptionButtons", bindingFlags);
if (fieldInfo != null)
{
Hashtable tab = fieldInfo.GetValue(dockingManager1) as Hashtable;
tab.Remove(this.GroupBar1);
}
Refer the sample at the following link that demonstrates the above,
http://www.syncfusion.com/uploads/redirect.aspx?&team=support&file=DockingManager-541423378.zipPlease let us know if you have concerns on this.
Regards
Vallarasu S.