Contract.Requires Method (Boolean, String)
Specifies a precondition contract for the enclosing method or property, and displays a message if the condition for the contract fails.
Assembly: mscorlib (in mscorlib.dll)
This method call must be at the beginning of a method or property, before any other code.
This contract is exposed to clients; therefore, it must only reference members that are at least as visible as the enclosing method.
Use this method instead of the Contract.Requires<TException>(Boolean, String) method when backward compatibility does not force you to throw a particular exception.
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