MessageContractAttribute Class


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Defines a strongly-typed class that corresponds to a SOAP message.

Namespace:   System.ServiceModel
Assembly:  System.ServiceModel (in System.ServiceModel.dll)


<AttributeUsageAttribute(AttributeTargets.Class Or AttributeTargets.Struct,
	AllowMultiple := False)>
Public NotInheritable Class MessageContractAttribute
	Inherits Attribute


Initializes a new instance of the MessageContractAttribute class.


Gets a value that indicates whether the message has a protection level.


Gets or sets a value that specifies whether the message body has a wrapper element.


Gets or sets a value that specified whether the message must be encrypted, signed, or both.


When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)


Gets or sets the name of the wrapper element of the message body.


Gets or sets the namespace of the message body wrapper element.


This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)


Returns the hash code for this instance.(Inherited from Attribute.)


Gets the Type of the current instance.(Inherited from Object.)


When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)


When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)


Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)


Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

Use the MessageContractAttribute attribute to specify the structure of the SOAP envelope for a particular message. Your service can then use the message as a parameter or return type in service operations. For information about controlling the serialization of the contents of a SOAP body without modifying the default SOAP envelope itself, see System.Runtime.Serialization.DataContractAttribute, Specifying Data Transfer in Service Contracts, and Using Data Contracts.


You cannot use custom message types in your service operation with regular serializable parameters. Either use custom message types or serializable parameters that are not Message objects. For details, see , Specifying Data Transfer in Service Contracts.

To implement a message contract for a type, annotate it with MessageContractAttribute and annotate one or more of the class's fields or properties with MessageBodyMemberAttribute, MessageHeaderAttribute, or MessageHeaderArrayAttribute.


System.ServiceModel.MessageParameterAttribute is not a message contract attribute and cannot be used in conjunction with MessageContractAttribute.

Use the Action and ReplyAction properties to specify the value of the <Action> element in the SOAP message.

  • Use the HasProtectionLevel and ProtectionLevel properties to indicate whether the SOAP message type has a protection level, and if so, what it is.

  • Use the IsWrapped property to indicate whether the message body has a wrapper element, and if so, use the WrapperName and WrapperNamespace properties to specify the name and namespace, respectively, of the wrapping element.

For more information, see Using Message Contracts.

The following code example shows the use of the MessageContractAttribute to control the SOAP envelope structure for both the request message and the response message, and the use of both the MessageHeaderAttribute (to create a SOAP header for the response message) and the MessageBodyMemberAttribute (to specify the bodies of both the request and response message). The code example contains an example of each message when sent.

Imports System.Runtime.Serialization
Imports System.ServiceModel
Imports System.ServiceModel.Channels

Namespace Microsoft.WCF.Documentation
  <ServiceContract(Namespace := "Microsoft.WCF.Documentation")> _
  Friend Interface IMessagingHello
	<OperationContract(Action := "http://GreetingMessage/Action", ReplyAction := "http://HelloResponseMessage/Action")> _
	Function Hello(ByVal msg As HelloGreetingMessage) As HelloResponseMessage
  End Interface

  <MessageContract> _
  Public Class HelloResponseMessage
	Private localResponse As String = String.Empty
	Private extra As String = String.Empty

	<MessageBodyMember(Name := "ResponseToGreeting", Namespace := "")> _
	Public Property Response() As String
		  Return localResponse
	  End Get
	  Set(ByVal value As String)
		  localResponse = value
	  End Set
	End Property

	<MessageHeader(Name := "OutOfBandData", Namespace := "", MustUnderstand:=True)> _
	Public Property ExtraValues() As String
		  Return extra
	  End Get
	  Set(ByVal value As String)
		  Me.extra = value
	  End Set
	End Property

'    The following is the response message, edited for clarity.
'    <s:Envelope>
'      <s:Header>
'        <a:Action s:mustUnderstand="1">http://HelloResponseMessage/Action</a:Action>
'        <h:OutOfBandData s:mustUnderstand="1" xmlns:h="">Served by object 13804354.</h:OutOfBandData>
'      </s:Header>
'      <s:Body>
'        <HelloResponseMessage xmlns="Microsoft.WCF.Documentation">
'          <ResponseToGreeting xmlns="">Service received: Hello.</ResponseToGreeting>
'        </HelloResponseMessage>
'      </s:Body>    
'    </s:Envelope>
  End Class
  <MessageContract> _
  Public Class HelloGreetingMessage
	Private localGreeting As String

	<MessageBodyMember(Name := "Salutations", Namespace := "")> _
	Public Property Greeting() As String
		  Return localGreeting
	  End Get
	  Set(ByVal value As String)
		  localGreeting = value
	  End Set
	End Property
  End Class

'   The following is the request message, edited for clarity.
'    <s:Envelope>
'      <s:Header>
'        <!-- Note: Some header content has been removed for clarity.
'        <a:Action>http://GreetingMessage/Action</a:Action> 
'        <a:To s:mustUnderstand="1"></a:To>
'      </s:Header>
'      <s:Body u:Id="_0" xmlns:u="">
'        <HelloGreetingMessage xmlns="Microsoft.WCF.Documentation">
'          <Salutations xmlns="">Hello.</Salutations>
'        </HelloGreetingMessage>
'      </s:Body>
'   </s:Envelope>

  Friend Class MessagingHello
	  Implements IMessagingHello
	Public Function Hello(ByVal msg As HelloGreetingMessage) As HelloResponseMessage Implements IMessagingHello.Hello
	  Console.WriteLine("Caller sent: " & msg.Greeting)
	  Dim responseMsg As New HelloResponseMessage()
	  responseMsg.Response = "Service received: " & msg.Greeting
	  responseMsg.ExtraValues = String.Format("Served by object {0}.", Me.GetHashCode().ToString())
	  Console.WriteLine("Returned response message.")
	  Return responseMsg
	End Function
  End Class
End Namespace

Universal Windows Platform
Available since 8
.NET Framework
Available since 3.0
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0

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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