ASP.NET Web-API不序列化readonly属性

I migrated an API method from a standard MVC action to the new asp.net Web-API beta and suddenly a read only property is no longer serialized (both returning JSON). Is this expected behaviour?

我将API方法从标准MVC操作迁移到新的asp.net Web-API beta,突然只读取属性不再序列化(都返回JSON)。这是预期的行为吗?

Edit: Added code sample

编辑:添加代码示例

I have both Newtonsoft.Json 4.0.8 and System.Json 4.0 referenced through nuget packages

我有通过nuget包引用的Newtonsoft.Json 4.0.8和System.Json 4.0

        public IQueryable<Car> Gets()
        {
             return _carRepository.GetCars();
        }

        public class Car
        {
            public IEnumerable<Photo> Photos
            {
                get { return _photos; }
            }

            public string PreviewImageUrl // No longer serialized
            {
                get
                {
                     var mainImage = Photos.FirstOrDefault(o => o.IsMainPreview) Photos.FirstOrDefault();
                        return mainImage != null ? mainImage.Url : (string.Empty);
                    }
                }
             }
         }

2 个解决方案

#1

The JsonMediaTypeFormatter that ships with the Beta uses a serializer that does not support read-only properties (since they would not round-trip correctly). We are planning on addressing this for the next realese.

Beta附带的JsonMediaTypeFormatter使用不支持只读属性的序列化程序(因为它们不能正确往返)。我们正在计划为下一个问题解决这个问题。

In the mean-time you could use a custom JSON MediaTypeFormatter implementation that uses Json.NET (there's one available here) instead of the built-in formatter.

在平均时间内,您可以使用自定义JSON MediaTypeFormatter实现,该实现使用Json.NET(这里有一个可用)而不是内置格式化程序。

Update: Also check out Henrik's blog about hooking up a JSON.NET formatter: http://blogs.msdn.com/b/henrikn/archive/2012/02/18/using-json-net-with-asp-net-web-api.aspx

更新:另请参阅Henrik的博客,了解如何连接JSON.NET格式化程序:http://blogs.msdn.com/b/henrikn/archive/2012/02/18/using-json-net-with-asp-net-网络api.aspx

#2

I don't know if this is an expected behavior or not. I would say that this is expected for input parameters (because you cannot set their values) but not for output parameters. So I would say this is a bug for an output parameter. And here's an example illustrating the issue:

我不知道这是否是预期的行为。我会说这是输入参数(因为你不能设置它们的值)而不是输出参数。所以我想说这是输出参数的错误。这是一个说明问题的例子:

Model:

public class Product
{
    public Product()
    {
        Prop1 = "prop1 value";
        Prop2 = "prop2 value";
        Prop3 = "prop3 value";
    }

    public string Prop1 { get; set; }

    [ReadOnly(true)]
    public string Prop2 { get; set; }

    public string Prop3 { get; protected set; }
}

Controller:

public class ProductsController : ApiController
{
    public Product Get(int id)
    {
        return new Product();
    }
}

Request:

api/products/5

Result:

{"Prop1":"prop1 value","Prop2":"prop2 value"}

So if the property doesn't have a public setter it is not serialized which doesn't seem normal as the Product class is used as output in this case.

因此,如果属性没有公共setter,那么它不是序列化的,这似乎不正常,因为在这种情况下Product类被用作输出。

I would suggest opening a connect ticket so that Microsoft can fix this before the release or at least tell that this is by design.

我建议打开连接票,以便Microsoft可以在发布之前修复此问题,或者至少告诉它是设计的。

#1