true if the UniArray is read-only; otherwise, false.
Remarks
A collection that is read-only does not allow the add, remove, or modify elements after the collection is created.
Requirements
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2