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)
'Declaration <ConditionalAttribute("CONTRACTS_FULL")> _ Public Shared Sub Requires ( _ condition As Boolean, _ userMessage As String _ )
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(Of TException)(Boolean, String) method when backward compatibility does not force you to throw a particular exception.
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.