Web API发布中的数据合同强制设置datevalue

Question

我有一个从Angular / Json客户端调用的WepApi，该客户端首先序列化为在EF代码中创建的模型。 我想发布产品模型并在post / save函数内设置changedate属性。 我得到ModelState.IsValid = false，是否有任何工作可以保留我的ef模型属性

[Required]  
public DateTime ChangeDate { get; set; }

得到此错误托盘过帐

{“ $ id”：“ 1”，“ Message”：“发生错误。”，“ ExceptionMessage”：“类型'Entity.Product'的属性'ChangeDate'无效。值类型的属性标记为[Required]还必须标记有[DataMember（IsRequired = true）]才能被识别为必需。考虑使用[DataContract]声明类型

CODE型号

[DataContract]
public class Product
{
    public Product()
    {
        ChangeDate = DateTime.Now;
    }

    //Serialization
    [DataMember]
    //DataAnnotations
    [DisplayName("ProductId")]
    [Description("ProductId")]
    public int ProductId { get; set; }

    //Serialization
    [DataMember(IsRequired = true)]
    //DataAnnotations
    [DisplayName("ChangeDate")]
    [Description("Date when product last was changed")]
    [Required]
    [DisplayFormat(DataFormatString = "{0:d}")]
    public DateTime ChangeDate { get; set; }

    //Serialization
    [DataMember]
    //DataAnnotations
    [DisplayName("Name")]
    [Description("Name")]
    [Required(ErrorMessage = " ")]
    [StringLength(100)]
    public String Name { get; set; } 


    public HttpResponseMessage Post(Entity.Product product,Boolean directSave = true)
    {
        if (ModelState.IsValid)
        {
            product.ChangeDate = DateTime.Now;
            _productRepository.Add(product);
            if (directSave)
                _context.Save();

            var response = Request.CreateResponse(HttpStatusCode.Created, product);
            response.Headers.Location = GetLocation(product.ProductId);
            return response;
        }

        return Request.CreateResponse(HttpStatusCode.BadRequest);
    }