WCF - Data Contract - Day 4

1. Day 1 - WCF Introduction and Contracts
2. Day 2: WCF Fault Contacts
3. Day 3: WCF Message Exchange Patterns

DataContract

DataContractAttribute

• Name - It determines the type name as it is generated in the resulting schema.
• Namespace - It sets the target namespace of the schema.

DataMemberAttribute

• EmitDefaultValue - If you want to add default values in the serialization then set the EmitDefaultValue to true else EmitDefaultValue to false. By default it is true.
• IsRequired - It controls the minOccurs attribute for the schema element. The default value is false.
• Name - It creates the schema element name generated for the member.
• Order - It maintains the order of each element in the schema. By default it appears alphabetically.

• For example, you set the EmitDefaultValue to false and IsRequired to true and you are not assigning any value, at that time it creates a problem. Because the serializer emits the default value and we are not passing any value, on the other side it is required. That is why it throws an error.
• If you apply a data member attribute to both property and field, then it generates duplicate members in the schema.

• Create one DataContract for Place. Add the data members PlaceCode and PlaceName.
• Set the order for the data members and set IsRequired to true for PlaceCode.
• Create one OperationContract with return type Place.
  
  1. namespace DataContractServiceApp
  2. {
  3. [ServiceContract]
  4. public interface IService1
  5. {
  6. [OperationContract]
  7. Place GetPlace(string PlaceCode);
  8. }
  10. [DataContract(Name ="Place", Namespace ="")]
  11. public classPlace
  12. {
  13. [DataMember(Name ="PlaceCode", Order = 1, IsRequired=true)]
  14. public string PlaceCode;
  15. [DataMember(Name ="PlaceName", Order = 2)]
  16. public string PlaceName;
  17. }
  18. }
• In the service class, the GetPlace method is implemented and in that we create an object of place, assign some values to it and return a Place object.
  
  1. namespace DataContractServiceApp
  2. {
  3. public class Service1 : IService1
  4. {
  5. public Place GetPlace(string PlaceCode)
  6. {
  7. Place place = new Place();
  8. // Get placename by placecode from database.
  9. return place;
  10. }
  11. }
  12. }