ServiceContractAttribute Class
Collapse the table of content
Expand the table of content

ServiceContractAttribute Class

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Indicates that an interface or a class defines a service contract in a Windows Phone client application.


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

[AttributeUsageAttribute(AttributeTargets.Class|AttributeTargets.Interface, Inherited = false, 
	AllowMultiple = false)]
public sealed class ServiceContractAttribute : Attribute

The ServiceContractAttribute type exposes the following members.

Public methodServiceContractAttributeInitializes a new instance of the ServiceContractAttribute class.

Public propertyCallbackContractGets or sets the type of callback contract when the contract is a duplex contract.
Public propertyConfigurationNameGets or sets the name used to locate the service in an application configuration file.
Public propertyNameGets or sets the name for the <portType> element in Web Services Description Language (WSDL).
Public propertyNamespaceGets or sets the namespace of the <portType> element in Web Services Description Language (WSDL).

Public methodEqualsInfrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeReturns the hash code for this instance. (Inherited from Attribute.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodMatchWhen overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)

Use the ServiceContractAttribute attribute on an interface (or class) to define a service contract. Then use the OperationContractAttribute attribute on one or more of the class (or interface) methods to define the contract's service operations.

The information expressed by a ServiceContractAttribute and its interface are loosely related to the Web Services Description Language (WSDL) <portType> element. A service contract is used on the service to specify what the service’s endpoint exposes to callers. It is also used on the client to specify the contract of the endpoint with which the client communicates.


An interface or class that is marked with ServiceContractAttribute must also have at least one method marked with the OperationContractAttribute attribute to expose any functionality. See the Examples section for a code example of the most basic use of the two attributes to define and implement a service.

Use the ServiceContractAttribute properties to modify the service contract.

  • The Name and Namespace properties control the name and namespace of the contract in the WSDL <portType> element.

  • The CallbackContract property specifies the return contract in a two-way (duplex) conversation.

Services implement service contracts, which represent the data exchange that a service type supports. A service class can implement a service contract (by implementing an interface marked with ServiceContractAttribute that has methods marked with OperationContractAttribute) or it can be marked with the ServiceContractAttribute and apply the OperationContractAttribute attribute to its own methods. (If a class implements an interface marked with ServiceContractAttribute, it cannot be itself marked with ServiceContractAttribute.) Methods on service types that are marked with the OperationContractAttribute are treated as part of a default service contract specified by the service type itself.

For more information about

service operations, see OperationContractAttribute.

By default, the Name and Namespace properties are the name of the contract type and, respectively. It is recommended that service contracts explicitly set their names and namespaces using these properties. Doing so builds a contract that is not directly connected to the managed type information, enabling you to re-factor your managed code and namespaces without breaking the contract as it is expressed in WSDL.

Clients either use the service contract interface (the interface marked with ServiceContractAttribute) to create a channel to the service or they use the client objects (which combine the type information of the service contract interface with the ClientBase<TChannel> class) to communicate with your service.

Using a ServiceContractAttribute class or interface to inherit from another ServiceContractAttribute class or interface extends the parent contract. For example, if an IChildContract interface is marked with ServiceContractAttribute and inherited from another service contract interface, IParentContract, the IChildContract service contract contains the methods of both IParentContract and IChildContract. Extending contracts (whether on classes or interfaces) is very similar to extending managed classes and interfaces.

The most flexible approach to creating clients is to define service contract interfaces first and then have your client class implement that interface. Building clients directly by marking a class with ServiceContractAttribute and its methods with OperationContractAttribute works as well.


If you use this API in your app, you must specify the following capabilities in the app manifest. Otherwise, your app might not work correctly or it might exit unexpectedly.


Windows Phone 8, Windows Phone OS 7.1

For more info, see App capabilities and hardware requirements for Windows Phone 8.

    //The following code contains an example of a duplex contract that contains a callback contract.
        Name = "SampleContract", 
        Namespace = "http://sample.service.contract", 
        CallbackContract = typeof(IDuplexClient))]
    public interface IDuplexService
        [OperationContract(IsOneWay = true)]
        void Order(string name, int quantity);

    public interface IDuplexClient
        [OperationContract(IsOneWay = true)]
        void Receive(Order order);

    public class Order
        public OrderStatus Status { get; set; }
        public List<string> Payload { get; set; }

    public enum OrderStatus

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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

© 2017 Microsoft