c# - WCF 服务 - 序列化 Linq 参数

Question

我有一个简单的类:

[DataContract]
public class Book
{
    [DataMember]
    public Int32 ID { get; set; }

    [DataMember]
    public Nullable<Int32> AuthorID { get; set; }     
}

这是通过 WCF 服务检索的，例如:

public class BookService : IBookService
    {
        IService _service;

        public BookService()
        {
            _service = new BookService();
        }

        public IEnumerable<Book> GetBooks()
        {
            var Books = _service.GetBooks();
            return Books;
        }                
    }

我现在想扩展它以包含一个附加函数，该函数允许 LINQ 查询包含 Book 类的附加属性(上面的简化示例中未显示)。这个函数(在包含并从 MVC 应用程序中调用时有效)是:

    public IEnumerable<Book> GetBooks(params Expression<Func<Book, object>>[] includes)
    {
        var Books = _service.GetBooks(Expression<Func<Book, object>>[]>(includes));
        return Books;
    }

但是，当从 WCF 服务运行时，这会生成错误，因为它无法序列化:

System.ServiceModel.Description.DataContractSerializerOperationBehavior contract: http://tempuri.org/:IBookService ----> System.Runtime.Serialization.InvalidDataContractException: Type 'System.Linq.Expressions.Expression1[System.Func2[Foo.Book,System.Object]]' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. If the type is a collection, consider marking it with the CollectionDataContractAttribute.

我将 DataContract/DataMember 属性添加到类中，以便它可以被序列化，但是我不确定我需要做什么才能允许函数参数被序列化。

有人知道我可以做些什么来允许在 WCF 服务中使用此功能吗？

Answer 1

这可能与表达式的使用有关吗？:

Why would you use Expression<Func<T>> rather than Func<T>?