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 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.