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, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.