This API supports the .NET Framework infrastructure and is not intended to be used directly from your code.
Indicates that a modified method argument should be interpreted as having object passed-by-value semantics. This modifier is applied to reference types. This class cannot be inherited.
Assembly: mscorlib (in mscorlib.dll)
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.