Service Contract Operationcontract and Datacontract in Wcf
These additional errors can be generated by triggering an Error Exception of the corresponding data contract type. For more information, see Handling Exceptions and Errors. To create a service contract, you define an interface with associated methods that are representative of a collection of service operations, and then decorate the interface/class with the ServiceContract attribute to indicate that it is a service contract. The interface methods that are to be included in the service contract are marked with the OperationContract attribute. In 90% of cases, DataContract is sufficient, you only need message contracts if you need to control the layout of your SOAP messages very precisely and very specifically. In most cases, you don`t have to. So, the service contract and the data contract are two completely separate parties that work together to run a WCF service – it`s not that one can replace the other or anything. I used self-hosting in this project, to create this project, you can simply take a « console application » project while choosing in the project wizard option. Let`s call it « ContractLibHost », this application hosts the service itself.
Let`s do some housework before writing code for the MaxItemsInObjectGraph host application and IgnoreExtensionDataObject can be controlled by configuration using the dataContractSerializer endpoint or the service behavior, as shown in the following example. This operation can return a normal message that contains a floating-point number or an error message that contains an error code and description. You can do this by triggering an ExceptionException in your service implementation. The service defines 3 methods as exposed operation(s) of the service. When describing services with Web Services Description Language (WSDL), the two commonly used styles are Document and Remote Procedure Call (RPC). In the document style, the entire body of the message is described using the schema, and the WSDL describes the different parts of the message body by referencing the elements of that schema. In the RPC style, the WSDL references a schema type for each part of the message, not an element. In some cases, you may need to select one of these styles manually. To do this, apply the DataContractFormatAttribute attribute and set the Style property (if DataContractSerializer is used) or set Style to the XmlSerializerFormatAttribute attribute (if you are using xmlSerializer).
Add a new class file named CategoryService under the CategoryServices folder. CategoryService implements the ICategoryService service contract from the NorthwindContracts assembly. The following is the implementation of each OperationContract of the ICategoryService service contract. By default, Windows Communication Foundation (WCF) uses a serializer called a data contract serializer to serialize and deserialize data (convert to XML). All primitive types of the .NET Framework, such as . B integers and strings, and some types treated as primitives, such as . B DateTime and XmlElement, can be serialized without further preparation and are considered types with standard data contracts. Many types of the .NET Framework also have existing data contracts. For a complete list of serializable types, see Types Supported by the Data Contract Serializer. A service contract defines the operations that the service makes available to the outside world. A service contract is the interface of the WCF service and tells the outside world what the service can do.
They can have service level settings, such as . B is the name of the service and the namespace of the service. Another way to describe messages in operations is to use the Stream class or one of its derived classes in a task contract or as a member of the message contract body (in which case, it must be the only element). Incoming messages must be of type Stream: you cannot use derived classes. Message contracts give you full control over the contents of the SOAP header as well as the structure of the SOAP body. A message contract is used to control the structure of a message body and the serialization process. It is used to send/access the information in the soap header. With a message contract, we can customize the settings sent with a SOAP message between the client and the server. You may need it if you have a communication partner with whom you have agreed on a very specific format and you need to customize your SOAP messages to exactly match the specified layout. This is pretty much the only valid scenario where you must and should use message contracts. A data contract defines the type of information data exchanged between the customer and the service. .