title: How do I instruct a custom JSON.NET JsonConverter to recognize that a particular property has already been serialized upstream?
body: <p>I have a touch of a predicament.  I have a collection of <code>System.Security.Claims.Claim</code> and the constructor of Claim requires the <code>value</code> parameter to contain a string.  The value of a particular claim needs to be a <code>JArray</code> that contains <code>JObject</code> and I can easily enough walk my structure during creation and build what I need to build, but I can't figure out how to instruct the Serializer to keep its hands off of <em>that</em> particular Claim.</p>
  
  <pre><code>string content = await response.Content.ReadAsStringAsync();
  JObject json = JObject.Parse(content);
  List&lt;JObject&gt; foos = new List&lt;JObject&gt;();
  var foosComingFromSomewhereElseWithADifferentStructure = json["foos"];
  bool first = true;
  foreach (var _foo in foosComingFromSomewhereElseWithADifferentStructure.Children&lt;JObject&gt;())
  {
     JObject foo = new JObject();
     string bar = (string)_foo["quux"].Value&lt;JToken&gt;();
     string baz = (string)_foo["inga"].Value&lt;JToken&gt;();
     foo.Add("Baz", baz);
     foo.Add("Bar", bar);
     foos.Add(foo);
  }
  
  claims.Add(new Claim("FooBar", (string)JsonConvert.SerializeObject(foos)));
  </code></pre>
  
  <p>After the block of code above runs, I continue processing and I then need to pass the whole enchilada through a Json Serializer ( my serialization essentially needs to be performed in multiple passes)</p>
  
  <p>So if I were to <em>now</em> need to pass the list of claims through yet another JSON.NET <code>JsonConverter</code>, how would I best declare to the Serializer to keep its hands off of FooBar because its value has already been prepared as JSON?</p>
  
  <p>Right now, my serializer is spitting out:</p>
  
  <pre><code>{
     "FooBar": "[{\"Baz"\":\"inga\",\"Bar\":\"quux\"}]
  }
  </code></pre>
  
  <p>when I need it to be spitting out</p>
  
  <pre><code>{
     "FooBar": [{"Baz":"inga","Bar":"quux"}]
  }
  </code></pre>