How can I parse JSON string from HttpClient?

There are three ways that come to mind.

1. Assuming the json is consistent and the structure of the response will not change frequently, I would use a tool like json2csharp or jsonutils to create c# classes.

   then call:

   {GeneratedClass} obj = JsonConvert.DeserializeObject<{GeneratedClass}>(result);
   

   This will give you a strongly typed object that you can use.

2. You can skip the class generation and use a dynamic object:

   dynamic obj = JsonConvert.DeserializeObject<dynamic>(result)
   

   and access properties such as:

   obj.dialog.prompt;
   

3. You can use a JObject and access its properties using strings

   JObject obj = JsonConvert.DeserializeObject(result);
   
   obj["dialog"]["prompt"]
   

You want to have a look here: http://www.newtonsoft.com/json/help/html/deserializeobject.htm

Create a class with the same structure like your XML. Then your variable s is an instance of this class and you can deserialize the json to the class structure.

In your case your property should be s.dialog.prompt.

Edited :

Import Newtonsoft.Json

JObject s = JObject.Parse(result);
string yourPrompt = (string)s["dialog"]["prompt"];

By installing the NuGet package Microsoft.AspNet.WebApi.Client like this:

PM> Install-Package Microsoft.AspNet.WebApi.Client

With:

using Newtonsoft.Json;

you could save one step by directly reading the content as a JObject:

dynamic response = await response.Content.ReadAsAsync<JObject>();
string prompt = response.dialog.prompt.ToString();

Note: This requires the response content to be of Content-Type "application/json".