ServiceKnownTypeAttribute 類別

定義

命名空間:

System.ServiceModel

組件:

System.ServiceModel.Primitives.dll

套件:

System.ServiceModel.Primitives v6.2.0

Source:

ServiceKnownTypeAttribute.cs

指定在序列化或還原序列化時，服務所使用的已知型別。

public ref class ServiceKnownTypeAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Interface | System.AttributeTargets.Method, AllowMultiple=true, Inherited=true)]
public sealed class ServiceKnownTypeAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Interface | System.AttributeTargets.Method, AllowMultiple=true, Inherited=true)>]
type ServiceKnownTypeAttribute = class
    inherit Attribute

Public NotInheritable Class ServiceKnownTypeAttribute
Inherits Attribute

繼承

Object

Attribute

ServiceKnownTypeAttribute

屬性

AttributeUsageAttribute

範例

下列範例會將 ServiceKnownTypeAttribute 屬性套用至 介面，其中 屬性會指定方法名稱和宣告類型。

// Define a service contract and apply the ServiceKnownTypeAttribute
// to specify types to include when generating client code.
// The types must have the DataContractAttribute and DataMemberAttribute
// applied to be serialized and deserialized. The attribute specifies the
// name of a method (GetKnownTypes) in a class (Helper) defined below.
[ServiceKnownType("GetKnownTypes", typeof(Helper))]
[ServiceContract()]
public interface ICatalog
{
    // Any object type can be inserted into a Hashtable. The
    // ServiceKnownTypeAttribute allows you to include those types
    // with the client code.
    [OperationContract]
    Hashtable GetItems();
}

// This class has the method named GetKnownTypes that returns a generic IEnumerable.
static class Helper
{
    public static IEnumerable<Type> GetKnownTypes(ICustomAttributeProvider provider)
    {
        System.Collections.Generic.List<System.Type> knownTypes =
            new System.Collections.Generic.List<System.Type>();
        // Add any types to include here.
        knownTypes.Add(typeof(Widget));
        knownTypes.Add(typeof(Machine));
        return knownTypes;
    }
}

[DataContract()]
public class Widget
{
    [DataMember]
    public string Id;
    [DataMember]
    public string Catalog;
}

[DataContract()]
public class Machine : Widget
{
    [DataMember]
    public string Maker;
}

' Define a service contract and apply the ServiceKnownTypeAttribute
' to specify types to include when generating client code. 
' The types must have the DataContractAttribute and DataMemberAttribute
' applied to be serialized and deserialized. The attribute specifies the 
' name of a method (GetKnownTypes) in a class (Helper) defined below.
<ServiceKnownType("GetKnownTypes", GetType(Helper)), ServiceContract()>  _
Public Interface ICalculator
    ' Any object type can be inserted into a Hashtable. The 
    ' ServiceKnownTypeAttribute allows you to include those types
    ' with the client code.
    <OperationContract()>  _
    Function GetItems() As Hashtable 
End Interface 

' This class has the method named GetKnownTypes that returns a generic IEnumerable.
Friend Class Helper
    Public Shared  Function GetKnownTypes(provider As ICustomAttributeProvider) _
     As IEnumerable(of Type) 
        Dim knownTypes As List(Of Type) = New List(Of Type)
        ' Add any types to include here.
        knownTypes.Add(GetType(Widget))
        knownTypes.Add(GetType(Machine))
        Return knownTypes
    End Function 
End Class 

<DataContract()>  _
Public Class Widget
    <DataMember()>  _
    Public Id As String
    <DataMember()>  _
    Public Catalog As String
End Class 

<DataContract()>  _
Public Class Machine
    Inherits Widget
    <DataMember()>  _
    Public Maker As String
End Class

或者，將此屬性套用在介面上，以指定要包含的已知型別。

// Apply the ServiceKnownTypeAttribute to the
// interface specifying the type to include. Apply
// the attribute more than once if needed.
[ServiceKnownType(typeof(Widget))]
[ServiceKnownType(typeof(Machine))]
[ServiceContract()]
public interface ICatalog2
{
    // Any object type can be inserted into a Hashtable. The
    // ServiceKnownTypeAttribute allows you to include those types
    // with the client code.
    [OperationContract]
    Hashtable GetItems();
}

' Apply the ServiceKnownTypeAttribute to the 
' interface specifying the type to include. Apply the attribute
' more than once, if needed.
<ServiceKnownType(GetType(Widget)), ServiceKnownType(GetType(Machine)), _
 ServiceContract()>  _
Public Interface ICalculator2
    ' Any object type can be inserted into a Hashtable. The 
    ' ServiceKnownTypeAttribute allows you to include those types
    ' with the client code.
    <OperationContract()>  _
    Function GetItems() As Hashtable 
End Interface

備註

ServiceKnownTypeAttribute用於建立 Windows Communication Foundation (WCF) 服務合約 (介面來定義服務及其方法) 。 已知類型是序列化或還原序列化發生時，可能會出現在物件圖形中的類型。 如需已知型別的詳細資訊，請參閱 資料合約已知型別。

若要使用 MethodName 屬性，請建立類別，其中包含方法 (或方法) 傳回類型陣列 (每個都是已知類型) 。 套用 屬性時，請將 設定 methodName 為傳回型別清單的方法名稱，並將 設定 declaringType 為包含 方法的類型。 方法必須傳回實作 介面的類型 IEnumerable<T> 。 方法也必須包含 類型的 ICustomAttributeProvider 參數。

您亦可將此屬性套用在介面、類別或方法上數次，且每次指定一個新的已知型別。

注意

您可以在 Microsoft Visual Basic 或 C# 程式碼中使用該字 ServiceKnownType ，而不是較長 ServiceKnownTypeAttribute 的 。

建構函式

ServiceKnownTypeAttribute(String)	初始化 ServiceKnownTypeAttribute 類別的新執行個體，並指定傳回已知型別的方法名稱。
ServiceKnownTypeAttribute(String, Type)	使用傳回已知型別的方法名稱和包含傳回已知型別之方法的型別，初始化 ServiceKnownTypeAttribute 類別的新執行個體。
ServiceKnownTypeAttribute(Type)	使用指定的已知型別來初始化 ServiceKnownTypeAttribute 類別的新執行個體。

屬性

DeclaringType	取得包含了傳回已知型別的方法的型別。
MethodName	取得傳回已知型別之集合的方法名稱。
Type	可包含在物件圖形中的已知型別。
TypeId	在衍生類別中實作時，取得這個 Attribute 的唯一識別碼。 (繼承來源 Attribute)

方法

Equals(Object)	傳回值，這個值指出此執行個體是否與指定的物件相等。 (繼承來源 Attribute)
GetHashCode()	傳回這個執行個體的雜湊碼。 (繼承來源 Attribute)
GetType()	取得目前執行個體的 Type。 (繼承來源 Object)
IsDefaultAttribute()	在衍生類別中覆寫時，表示這個執行個體的值是衍生類別的預設值。 (繼承來源 Attribute)
Match(Object)	在衍生類別中覆寫時，會傳回值，表示這個執行個體是否等於指定物件。 (繼承來源 Attribute)
MemberwiseClone()	建立目前 Object 的淺層複製。 (繼承來源 Object)
ToString()	傳回代表目前物件的字串。 (繼承來源 Object)

另請參閱

• DataContractAttribute
• DataMemberAttribute
• 資料合約已知型別