Contract.Ensures Method (Boolean, String)

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Specifies a postcondition contract for a provided exit condition and a message to display if the condition is false.

Namespace: System.Diagnostics.Contracts
Assembly: mscorlib (in mscorlib.dll)

Syntax

'Declaration
<ConditionalAttribute("CONTRACTS_FULL")> _
Public Shared Sub Ensures ( _
    condition As Boolean, _
    userMessage As String _
)

[ConditionalAttribute("CONTRACTS_FULL")]
public static void Ensures(
    bool condition,
    string userMessage
)

condition
Type: System.Boolean
The conditional expression to test. The expression may include OldValue<T> and Result<T> values.

userMessage
Type: System.String
The message to display if the expression is not true.

The condition parameter specifies a postcondition that is expected to be true when the enclosing method or property returns normally.

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.
You must use the binary rewriter (available at Code Contracts on the MSDN DevLabs Web site) for run-time enforcement of this postcondition.
If userMessage is not a constant string literal, the contract may not be understood by tools.

Supported in: 5, 4

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.