Json.NET (Newtonsoft.Json)

Json.NET is a high-performance JSON framework for .NET designed for speed and flexibility. It provides several core capabilities:

• JSON Serialization: Flexible conversion between .NET objects and JSON strings.
• LINQ to JSON: A way to manually read and write JSON using LINQ-style queries.
• High Performance: Optimized to be faster than the built-in .NET JSON serializers.
• Formatting: Support for writing indented, human-readable JSON.
• XML Interop: Ability to convert JSON to and from XML.

Json.NET provides different library packages depending on your target .NET framework or platform. Choose the package that matches your environment:

Standard Frameworks

• net45: .NET 4.5 and above
• net40: .NET 4.0
• net35: .NET 3.5
• net20: .NET 2.0 or Unity

.NET Standard

• netstandard1.0
• netstandard1.3
• netstandard2.0

Portable / Mobile / Web

• portable-net45+win8+wpa81+wp8: .NET 4.5, Windows Phone 8, Windows 8 Store
• portable-net40+win8+wpa81+wp8+sl5: .NET 4.0, Windows Phone 8, Windows 8 Store, Silverlight 5, MonoTouch, MonoDroid

Legacy / Specific Requirements

• For Compact Framework 3.5 and Silverlight 3.0: Use Json.NET 3.5
• For Silverlight 4.0 and Windows Phone 7: Use Json.NET 5

Convert a JSON string back into a .NET object using JsonConvert.DeserializeObject<T>. You must specify the target type T within the generic method call.

string json = @"{ 
  'Name': 'Bad Boys', 
  'ReleaseDate': '1995-4-7T00:00:00', 
  'Genres': [ 
    'Action', 
    'Comedy' 
  ] 
}";

Movie m = JsonConvert.DeserializeObject<Movie>(json);

string name = m.Name;
// Bad Boys

Use JObject and JArray to build and manipulate JSON structures dynamically without needing a predefined class schema. This approach allows for manual construction of JSON trees.

JArray array = new JArray();
array.Add("Manual text");
array.Add(new DateTime(2000, 5, 23));

JObject o = new JObject();
o["MyArray"] = array;

string json = o.ToString();
// {
//   "MyArray": [
//     "Manual text",
//     "2000-05-23T00:00:00"
//   ]
// }

Convert .NET objects into JSON strings using JsonConvert.SerializeObject. This method takes an object and produces a JSON representation of its properties.

Product product = new Product();
product.Name = "Apple";
product.Expiry = new DateTime(2008, 12, 28);
product.Sizes = new string[] { "Small" };

string json = JsonConvert.SerializeObject(product);
// {
//   "Name": "Apple",
//   "Expiry": "2008-12-28T00:00:00",
//   "Sizes": [
//     "Small"
//   ]
// }