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Converting JObject to a dynamic object

I am calling a REST endpoint from C# and I am receiving json which gets serialized into an object. One of the properties on this object is a dynamic property. The value of the dynamic property is set as a anonymous object on the server site like this:

myObject.MyDynamicProp = new { Id = "MyId2134", Name = "MyName" };

On the client site the value of the dynamic property from the json serialization is a JObject containing the following value:

{{
  "id": "MyId2134",
  "Name": "MyName"
}}

I would have expected to be able to access the properties like this:

var s = myObject.MyDynamicProp.Name;

but it does not find the Name property instead I have to get the value like this:

var s = myObject.MyDynamicProp["Name"].Value;

I tried converting the JObject into a dynamic object like this but it returns JObject:

var dyn = myObject.MyDynamicProp.ToObject<dynamic>();

How can I convert the dynamic property value such that I can call its properties directly?

var s = myObject.MyDynamicProp.Name;

UPDATE ...

I ran the following

 dynamic d = JsonConvert.DeserializeObject("{\"MyDynamicProp\": {\"id\": \"MyId2134\", \"Name\": \"MyName\"}}");
 string name = d.MyDynamicProp.Name;

Which gives me the following the error:

 {Microsoft.CSharp.RuntimeBinder.RuntimeBinderException:    `Newtonsoft.Json.Linq.JObject' does not contain a definition for `MyDynamicProp'
  at Microsoft.Scripting.Interpreter.ThrowInstruction.Run (Microsoft.Scripting.Interpreter.InterpretedFrame frame) [0x00027]

I would like to add that this is an Xamarin iOS project and the code is located in a PCL library.


I assumed there was a problem with my code but it looks like it is not possible to use dynamic types within a Xamarin iOS project. https://developer.xamarin.com/guides/ios/advanced_topics/limitations/

like image 236
doorman Avatar asked Apr 12 '16 07:04

doorman


1 Answers

It is actually quite easy. Instead of using var use dynamic on your JObject and you will be fine:

dynamic do = myObject.MyDynamicProp;

string name = do.Name;

From your fragment:

dynamic d = JsonConvert.DeserializeObject("{\"MyDynamicProp\": {\"id\": \"MyId2134\", \"Name\": \"MyName\"}}");
string name = d.MyDynamicProp.Name;

Console.WriteLine(name); // writes MyName

Why this works: As Richard explained, JObject derives indirectly from JToken which implements IDynamicMetaObjectProvider. It is that interface that allows dynamic to work.

like image 101
Patrick Hofman Avatar answered Oct 05 '22 02:10

Patrick Hofman