Obsolete or Deprecated in NET Framework
The .NET Framework and its supporting languages changes over time. Each new version release, it adds new types and type members that provide new functionality and also existing types and their members also change over the time. Although Obsolete or Deprecated features remain in the current version, their use may throw warning messages recommending alternate practices, and deprecation warns that this feature will be removed in the future versions.
Applying this attribute to a type or member indicates that the type or member will be removed from the future version. The Obsolete attribute can be used without arguments, but including an explanation of why the item is obsolete and what to use instead is recommended.
C# Source Code
VB.Net Source Code