Why datacontract in wcf is used

Build Web project and then Add Service reference to client side. Now we can access the service methods at client side.

View All. Data Contract in WCF. Priya Linge Updated date Sep 10, Next Recommended Reading. Windows 10 Vs Windows Visual Studio Vs Visual Studio Understanding Matplotlib With Examples.

Through the use of this method, in the exported schema, the access modifier can be generated as private. This method maps the Type of the surrogate to the original type. This method is optional for schema importation. When creating a surrogate that imports a schema and generates code for it, the next task is to define the type of a surrogate instance to its original type. If the generated code needs to reference an existing user type, this is done by implementing the GetReferencedTypeOnImport method.

When importing a schema, this method is called for every type declaration to map the surrogated data contract to a type. The string parameters typeName and typeNamespace define the name and namespace of the surrogated type.

The return value for GetReferencedTypeOnImport is used to determine whether a new type needs to be generated. This method must return either a valid type or null.

For valid types, the type returned will be used as a referenced type in the generated code. If null is returned, no type will be referenced and a new type must be created. If several surrogates exist, it is possible to perform the mapping for each surrogate type back to its initial type.

The ProcessImportedType method customizes any type created from schema importation. This method is optional. When importing a schema, this method allows for any imported type and compilation information to be customized.

During import, this method is called for every type generated. This includes changing the name, members, attributes, and many other properties of the CodeTypeDeclaration. By processing the CodeCompileUnit , it is possible to modify the directives, namespaces, referenced assemblies, and several other aspects.

The CodeCompileUnit parameter allows for modification for processing the code. Returning null results in the type declaration being discarded. Conversely, when returning a CodeTypeDeclaration , the modifications are preserved. If custom data is inserted during metadata export, it needs to be provided to the user during import so that it can be used. This custom data can be used for programming model hints, or other comments. The example above performs some changes on the schema imported.

The code preserves private members of the original type by using a surrogate. The default access modifier when importing a schema is public. Therefore, all members of the surrogate schema will be public unless modified, as in this example.

During export, custom data is inserted into the metadata about which members are private. The example looks up the custom data, checks whether the access modifier is private, and then modifies the appropriate member to be private by setting its attributes. Without this customization, the numpens member would be defined as public instead of private.

This method obtains custom data types defined from the schema. The method is optional for schema importation. The method is called at the beginning of schema export and import. The method returns the custom data types used in the schema exported or imported. The method should add additional known types to this collection. The known custom data types are needed to enable serialization and deserialization of custom data using the DataContractSerializer.

For more information, see Data Contract Known Types. Use the DataContractSerializer to perform serialization and deserialization of data with the surrogate.

The surrogate must also be specified. Create an instance of the ServiceHost for your service. For every ServiceEndpoint of the specified service host, find its OperationDescription. Search through the operation behaviors to determine if an instance of the DataContractSerializerOperationBehavior is found.

If no DataContractSerializerOperationBehavior is found, then create a new instance and set the DataContractSurrogate member of the new behavior to a new instance of the surrogate. Finally, add this new behavior to the current operation behaviors, as shown in the following example:.

To do this, directly modify the WsdlImporter used to import metadata. Import the metadata using the WsdlImporter class.

Otherwise, use the importer returned by the out parameter of the TryGetValue method. Use the ImportAllContracts method of the WsdlImporter to import all of the data contracts within the schema. During the last step, code is generated from the schemas loaded by calling into the surrogate. The surrogate needs to be added to the component responsible for generating XSD schema for data contract types, XsdDataContractExporter. To do this, either use a behavior that implements IWsdlExportExtension to modify the WsdlExporter , or directly modify the WsdlExporter used to export metadata.

Otherwise, use the exporter returned by the out parameter of the TryGetValue method. The following example shows a service contract an interface to which the ServiceContractAttribute and OperationContractAttribute attributes have been explicitly applied.

The example shows that primitive types do not require a data contract, while a complex type does. The following example shows how a data contract for the MyTypes. The IgnoreDataMemberAttribute attribute is only honored when used with unmarked types.

You can apply the DataMemberAttribute attribute to fields, and properties. Member accessibility levels internal, private, protected, or public do not affect the data contract in any way. The DataMemberAttribute attribute is ignored if it is applied to static members. During serialization, property-get code is called for property data members to get the value of the properties to be serialized. During deserialization, an uninitialized object is first created, without calling any constructors on the type.

Then all data members are deserialized. During deserialization, property-set code is called for property data members to set the properties to the value being deserialized. For a data contract to be valid, it must be possible to serialize all of its data members. Generic types are handled in exactly the same way as non-generic types.