ContractClassAttribute Classe
Definição
Especifica que um tipo separado contém os contratos de código para esse tipo.Specifies that a separate type contains the code contracts for this type.
public ref class ContractClassAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Delegate | System.AttributeTargets.Interface, AllowMultiple=false, Inherited=false)]
[System.Diagnostics.Conditional("DEBUG")]
[System.Diagnostics.Conditional("CONTRACTS_FULL")]
public sealed class ContractClassAttribute : Attribute
[<System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Delegate | System.AttributeTargets.Interface, AllowMultiple=false, Inherited=false)>]
[<System.Diagnostics.Conditional("DEBUG")>]
[<System.Diagnostics.Conditional("CONTRACTS_FULL")>]
type ContractClassAttribute = class
inherit Attribute
Public NotInheritable Class ContractClassAttribute
Inherits Attribute
- Herança
- Atributos
Exemplos
O exemplo a seguir mostra como usar o ContractClassAttribute atributo para especificar que os contratos para a IArray interface estão contidos na IArrayContracts classe.The following example shows how to use the ContractClassAttribute attribute to specify that the contracts for the IArray interface are contained in the IArrayContracts class.
#define CONTRACTS_FULL
using System;
using System.Diagnostics.Contracts;
// An IArray is an ordered collection of objects.
[ContractClass(typeof(IArrayContract))]
public interface IArray
{
// The Item property provides methods to read and edit entries in the array.
Object this[int index]
{
get;
set;
}
int Count
{
get;
}
// Adds an item to the list.
// The return value is the position the new element was inserted in.
int Add(Object value);
// Removes all items from the list.
void Clear();
// Inserts value into the array at position index.
// index must be non-negative and less than or equal to the
// number of elements in the array. If index equals the number
// of items in the array, then value is appended to the end.
void Insert(int index, Object value);
// Removes the item at position index.
void RemoveAt(int index);
}
[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);
}
}
#Const CONTRACTS_FULL = True
Imports System.Diagnostics.Contracts
' An IArray is an ordered collection of objects.
<ContractClass(GetType(IArrayContract))> _
Public Interface IArray
' The Item property provides methods to read and edit entries in the array.
Default Property Item(ByVal index As Integer) As [Object]
ReadOnly Property Count() As Integer
' Adds an item to the list.
' The return value is the position the new element was inserted in.
Function Add(ByVal value As Object) As Integer
' Removes all items from the list.
Sub Clear()
' Inserts value into the array at position index.
' index must be non-negative and less than or equal to the
' number of elements in the array. If index equals the number
' of items in the array, then value is appended to the end.
Sub Insert(ByVal index As Integer, ByVal value As [Object])
' Removes the item at position index.
Sub RemoveAt(ByVal index As Integer)
End Interface 'IArray
<ContractClassFor(GetType(IArray))> _
Friend MustInherit Class IArrayContract
Implements IArray
Function Add(ByVal value As Object) As Integer Implements IArray.Add
' Returns the index in which an item was inserted.
Contract.Ensures(Contract.Result(Of Integer)() >= -1) '
Contract.Ensures(Contract.Result(Of Integer)() < CType(Me, IArray).Count) '
Return 0
End Function 'IArray.Add
Default Property Item(ByVal index As Integer) As Object Implements IArray.Item
Get
Contract.Requires(index >= 0)
Contract.Requires(index < CType(Me, IArray).Count)
Return 0 '
End Get
Set(ByVal value As [Object])
Contract.Requires(index >= 0)
Contract.Requires(index < CType(Me, IArray).Count)
End Set
End Property
Public ReadOnly Property Count() As Integer Implements IArray.Count
Get
Contract.Requires(Count >= 0)
Contract.Requires(Count <= CType(Me, IArray).Count)
Return 0 '
End Get
End Property
Sub Clear() Implements IArray.Clear
Contract.Ensures(CType(Me, IArray).Count = 0)
End Sub
Sub Insert(ByVal index As Integer, ByVal value As [Object]) Implements IArray.Insert
Contract.Requires(index >= 0)
Contract.Requires(index <= CType(Me, IArray).Count) ' For inserting immediately after the end.
Contract.Ensures(CType(Me, IArray).Count = Contract.OldValue(CType(Me, IArray).Count) + 1)
End Sub
Sub RemoveAt(ByVal index As Integer) Implements IArray.RemoveAt
Contract.Requires(index >= 0)
Contract.Requires(index < CType(Me, IArray).Count)
Contract.Ensures(CType(Me, IArray).Count = Contract.OldValue(CType(Me, IArray).Count) - 1)
End Sub
End Class
Comentários
Os tipos marcados com esse atributo têm contratos de código que são incluídos em um tipo separado.Types that are marked with this attribute have code contracts that are included in a separate type. O tipo que contém os contratos é especificado no construtor.The type that contains the contracts is specified in the constructor.
Construtores
| ContractClassAttribute(Type) |
Inicializa uma nova instância da classe ContractClassAttribute.Initializes a new instance of the ContractClassAttribute class. |
Propriedades
| TypeContainingContracts |
Obtém o tipo que contém os contratos de código desse tipo.Gets the type that contains the code contracts for this type. |
| TypeId |
Quando implementado em uma classe derivada, obtém um identificador exclusivo para este Attribute.When implemented in a derived class, gets a unique identifier for this Attribute. (Herdado de Attribute) |
Métodos
| Equals(Object) |
Retorna um valor que indica se essa instância é igual a um objeto especificado.Returns a value that indicates whether this instance is equal to a specified object. (Herdado de Attribute) |
| GetHashCode() |
Retorna o código hash para a instância.Returns the hash code for this instance. (Herdado de Attribute) |
| GetType() |
Obtém o Type da instância atual.Gets the Type of the current instance. (Herdado de Object) |
| IsDefaultAttribute() |
Quando substituído em uma classe derivada, indica se o valor dessa instância é o valor padrão para a classe derivada.When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Herdado de Attribute) |
| Match(Object) |
Quando substituído em uma classe derivada, retorna um valor que indica se essa instância é igual a um objeto especificado.When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Herdado de Attribute) |
| MemberwiseClone() |
Cria uma cópia superficial do Object atual.Creates a shallow copy of the current Object. (Herdado de Object) |
| ToString() |
Retorna uma cadeia de caracteres que representa o objeto atual.Returns a string that represents the current object. (Herdado de Object) |
Implantações explícitas de interface
| _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) |
Mapeia um conjunto de nomes para um conjunto correspondente de identificadores de expedição.Maps a set of names to a corresponding set of dispatch identifiers. (Herdado de Attribute) |
| _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) |
Recupera as informações de tipo para um objeto, que pode ser usado para obter as informações de tipo para uma interface.Retrieves the type information for an object, which can be used to get the type information for an interface. (Herdado de Attribute) |
| _Attribute.GetTypeInfoCount(UInt32) |
Retorna o número de interfaces de informações do tipo que um objeto fornece (0 ou 1).Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Herdado de Attribute) |
| _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) |
Fornece acesso a propriedades e métodos expostos por um objeto.Provides access to properties and methods exposed by an object. (Herdado de Attribute) |