序列化ExpandoObject与ServiceStack.Text

问题描述

我想序列化与图书馆 ServiceStack.Text 的对象。这适用

I am trying to serialize objects with the library ServiceStack.Text . This works

using System.Dynamic;
using ServiceStack.Text;
var x = new {Value= 10, Product = "Apples"};                
Console.WriteLine(JsonSerializer.SerializeToString(x));

我得到的，因为我希望

I get, as I expect

{"Value":10,"Product":"Apples"}

然而

dynamic x = new ExpandoObject();
x.Value = 100;
x.Product = "Apples";
Console.WriteLine(JsonSerializer.SerializeToString(x));

我得到我吃惊的是

I get to my surprise

[{"Key":"Value","Value":100},{"Key":"Product","Value":"Apples"}]

为什么！这是怎么回事？

Why! What's going on?

第二，我怎么能得到我想要什么？的

推荐答案

ExpandoObject 工具 IConnection＆LT; KeyValuePair＆GT; 和的IEnumerable＆LT; KeyValuePair＆GT; ：

public sealed class ExpandoObject :
    IDynamicMetaObjectProvider,
    IDictionary<string, object>,
    ICollection<KeyValuePair<string, object>>,
    IEnumerable<KeyValuePair<string, object>>,
    IEnumerable, INotifyPropertyChanged

我的猜测是，在国内，ServiceStack串行器治疗 ExpandoObject 为的IEnumerable＆LT; KeyValuePair＆GT; ，和所以它系列化，以键/值对的JSON数组。

My guess is that internally, the ServiceStack serializer is treating the ExpandoObject as an IEnumerable<KeyValuePair>, and so it serializes to a JSON array of key/value pairs.

这不同于你的第一个（工作）code段，因为.NET实际上建立了一个真正的（匿名）类为您的数据，基本上它使：

This differs from your first (working) code snippet because .NET actually builds a real (anonymous) class for your data, basically it makes:

public class SomeNameTheCompilerMakesUp {
    internal int Value { get; set; }
    internal string Product { get; set; }
}

自动为您，所以当它被发送到串行化器，它正在与一个真正的类不动产，而 ExpandoObject 真的是由<$支持C $ C> [对象] 内部。

在一个侧面说明，微软 System.Web.Helpers.Json 进行同样的操作。该测试通过：

On a side-note, Microsoft's System.Web.Helpers.Json behaves the same way. This test passes:

    [TestMethod]
    public void ExpandoObjectSerializesToJsonArray()
    {
        dynamic anonType = new { Value = 10, Product = "Apples" };

        dynamic expando = new ExpandoObject();
        expando.Value = 10;
        expando.Product = "Apples";

        var anonResult = System.Web.Helpers.Json.Encode(anonType);
        var expandoResult = System.Web.Helpers.Json.Encode(expando);

        Assert.AreEqual("{\"Value\":10,\"Product\":\"Apples\"}", anonResult);
        Assert.AreEqual("[{\"Key\":\"Value\",\"Value\":10},{\"Key\":\"Product\",\"Value\":\"Apples\"}]", expandoResult);
    }

---

最后一个编辑：的

---

One final edit:

您可以使这项工作要通过旋转的方式你的 ExpandoObject 到词典＆LT;字符串，对象＆gt; 。需要说明的这个code是它复制数据到一本字典，让你有2份内存（或略小于，由于技术上的弦可能会扣留）。

You can make this work the way you want by turning your ExpandoObject into a Dictionary<string, object>. The caveat to this code is that it duplicates the data into a dictionary, so you have 2 copies in memory (or slightly less than, since technically the strings might be interned).

    [TestMethod]
    public void TestMethod1()
    {
        dynamic expando = new ExpandoObject();
        expando.Value = 10;
        expando.Product = "Apples";

        // copy expando properties to dictionary
        var dictionary = ((ExpandoObject)expando).ToDictionary(x => x.Key, x => x.Value);

        var expandoResult    = System.Web.Helpers.Json.Encode(expando);
        var dictionaryResult = System.Web.Helpers.Json.Encode(dictionary);

        Assert.AreEqual("[{\"Key\":\"Value\",\"Value\":10},{\"Key\":\"Product\",\"Value\":\"Apples\"}]", expandoResult);
        Assert.AreEqual("{\"Value\":10,\"Product\":\"Apples\"}", dictionaryResult);
    }

虽然，对于任何人遇到这样过去了，而实际上使用 System.Web.Helpers.Json ，更好的事情要做的只是包装你的 ExpandoObject 在 DynamicJsonObject 是这样的：

Although, for anyone that comes across this later, and is actually using System.Web.Helpers.Json, the better thing to do is just wrap your ExpandoObject in a DynamicJsonObject like this:

    [TestMethod]
    public void TestMethod1()
    {
        dynamic expando = new ExpandoObject();
        expando.Value = 10;
        expando.Product = "Apples";

        var dictionaryResult = System.Web.Helpers.Json.Encode(new DynamicJsonObject(expando));

        Assert.AreEqual("{\"Value\":10,\"Product\":\"Apples\"}", dictionaryResult);
    }

答一次，我通过努力，我发现了一个类似的问题在这里：How扁平化的ExpandoObject通过JsonResult在asp.net mvc的返回？

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