Checks whether this object is read-only and cannot be changed.
Assembly: PresentationFramework (in PresentationFramework.dll)
Classes that derive from SetterBase must call this method before applying any changes to the state of the object. If the object is read-only and you try to modify the state of the object, an exception is thrown.
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
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.