blog

Home / DeveloperSection / Blogs / WCF Contracts.

WCF Contracts.

James Smith6772 01-Aug-2011

Contracts in WCF


In WCF, all services expose contracts. The contract is a platform-neutral and standard way of describing what the service does. In this blog I will told you that which type of contracts available in WCF and how we can use them. This blog is only provides an introductory knowledge in WCF contracts.

WCF defines four types of contracts.

Service contracts


Service contracts define which type of operations the client can perform on the service. We used two types of attributes to define service contract.

ServiceContract- This attribute is used to define the Interface.

OperationContract- This attribute is used to define the method inside Interface.

Example of service contracts


[ServiceContract]

interface IServiceContract

{

   [OperationContract]

   string MyMethod( );

}

class Service : IServiceContract

{

   public string HelloWorld( )

   {

      return "Hello World";

   }

}

Data contracts


Data contracts define which data types are passed to and from the service. WCF defines implicit contracts for built-in types such as int and string, but we can easily define explicit opt-in data contracts for custom types.

There are two types of Data Contracts.

DataContract–DataContract  attribute used to define the class

DataMember –DataMember  attribute used to define the properties.

Example of Data contracts


[DataContract]

class ServiceContract

{

   [DataMember]

   public string Name;

   [DataMember]

   public string City;

}

If DataMember attributes are not specified for a properties in the class that property can't be passed to-from web service.

Fault contracts

Define which errors are raised by the service, and how the service handles and propagates errors to its clients.

Message contracts


Allow the service to interact directly with messages. Message contracts can be typed or untyped, and are useful in interoperability cases and when there is an existing message format we have to comply with.


Updated 18-Sep-2014

Leave Comment

Comments

Liked By