If you have ever happen to get "Type xxx is an invalid collection type since it has DataContract Attribute attribute" error at any time when ever publishing WCF service, Make sure you annotate your custom collections with CollectionDataContract attribute instead of DataContract attribute. This attribute will appropriate serialize and deserialize collection.
CollectionDataContract attribute is typically utilized in scenarios involving non-WCF providers/clients to extract exact shape of data. But, you loose one important benefit with "CollectionDataContract" is "Cross Collection Interchangeability". For instance, in case of homogeneous environment of WCF client and service though WCF service exposes List collections as response, client expecting different native collection type like ArrayList/Collection can still consume the collection.
You loose this benefit if you use CollectionDataContract attribute with Collection Types.
WCF also imposes additional requirements when using collections. Keep in mind of following items when exposing custom collections via WCF service or else custom collections are not serialized/deserialized.
CollectionDataContract attribute is typically utilized in scenarios involving non-WCF providers/clients to extract exact shape of data. But, you loose one important benefit with "CollectionDataContract" is "Cross Collection Interchangeability". For instance, in case of homogeneous environment of WCF client and service though WCF service exposes List
You loose this benefit if you use CollectionDataContract attribute with Collection Types.
WCF also imposes additional requirements when using collections. Keep in mind of following items when exposing custom collections via WCF service or else custom collections are not serialized/deserialized.
- Collection should support Add method.
- Collection should have default constructor.
