This documentation is archived and is not being maintained.

Contract.Ensures Method (Boolean)

Specifies a postcondition contract for the enclosing method or property.

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

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

Parameters

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

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.

  • You must use the binary rewriter (available at Code Contracts on the MSDN DevLabs Web site) for run-time enforcement of this postcondition.

The following example shows how to use the Ensures method to ensure that an expected value is returned. This code example is part of a larger example provided for the ContractClassAttribute class.


int IArray.Add(Object value)
{
    // Returns the index in which an item was inserted.
    Contract.Ensures(Contract.Result<int>() >= -1);
    Contract.Ensures(Contract.Result<int>() < ((IArray)this).Count);
    return default(int);
}


.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

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

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Show: