Artigo
11/18/2011

ContractClassForAttribute Class

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Specifies that a class is a contract for a type.

Inheritance Hierarchy

System.Object
System.Attribute
System.Diagnostics.Contracts.ContractClassForAttribute

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

Syntax

'Declaration
<ConditionalAttribute("CONTRACTS_FULL")> _
<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple := False, Inherited := False)> _
Public NotInheritable Class ContractClassForAttribute _
    Inherits Attribute

[ConditionalAttribute("CONTRACTS_FULL")]
[AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = false, Inherited = false)]
public sealed class ContractClassForAttribute : Attribute

The ContractClassForAttribute type exposes the following members.

Constructors

	Name	Description
	ContractClassForAttribute	Initializes a new instance of the ContractClassForAttribute class, specifying the type the current class is a contract for.

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Properties

	Name	Description
	TypeContractsAreFor	Gets the type that this code contract applies to.

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Methods

	Name	Description
	Equals	Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Returns the hash code for this instance. (Inherited from Attribute.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	Match	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Remarks

Types that are marked with this attribute represent a code contract for another type. The type that the contract applies to is specified in the constructor.

Examples

The following example shows how to use the ContractClassForAttribute attribute to specify the contracts for another type. This code example is part of a larger example provided for the ContractClassAttribute class.

[ContractClassFor(typeof(IArray))]
internal abstract class IArrayContract : IArray
{
    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);
    }
    Object IArray.this[int index]
    {
        get
        {
            Contract.Requires(index >= 0);
            Contract.Requires(index < ((IArray)this).Count);
            return default(int);
        }
        set
        {
            Contract.Requires(index >= 0);
            Contract.Requires(index < ((IArray)this).Count);
        }
    }
    public int Count
    {
        get
        {
            Contract.Requires(Count >= 0);
            Contract.Requires(Count < ((IArray)this).Count);
            return default(int);
        }
    }

    void IArray.Clear()
    {
        Contract.Ensures(((IArray)this).Count == 0);
    }

    void IArray.Insert(int index, Object value)
    {
        Contract.Requires(index >= 0);
        Contract.Requires(index <= ((IArray)this).Count);  // For inserting immediately after the end.
        Contract.Ensures(((IArray)this).Count == Contract.OldValue(((IArray)this).Count) + 1);
    }

    void IArray.RemoveAt(int index)
    {
        Contract.Requires(index >= 0);
        Contract.Requires(index < ((IArray)this).Count);
        Contract.Ensures(((IArray)this).Count == Contract.OldValue(((IArray)this).Count) - 1);
    }
}

Version Information

Silverlight

Supported in: 5, 4

Platforms

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

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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