Serializing a list to JSON

Solution 1:

If using .Net Core 3.0 or later;

Default to using the built in System.Text.Json parser implementation.

e.g.

using System.Text.Json;

var json = JsonSerializer.Serialize(aList);

alternatively, other, less mainstream options are available like Utf8Json parser and Jil: These may offer superior performance, if you really need it but, you will need to install their respective packages.

If stuck using .Net Core 2.2 or earlier;

Default to using Newtonsoft JSON.Net as your first choice JSON Parser.

e.g.

using Newtonsoft.Json;

var json = JsonConvert.SerializeObject(aList);

you may need to install the package first.

PM> Install-Package Newtonsoft.Json

For more details see and upvote the answer that is the source of this information.

For reference only, this was the original answer, many years ago;

// you need to reference System.Web.Extensions

using System.Web.Script.Serialization;

var jsonSerialiser = new JavaScriptSerializer();
var json = jsonSerialiser.Serialize(aList);

Solution 2:

You can also use Json.NET. Just download it at http://james.newtonking.com/pages/json-net.aspx, extract the compressed file and add it as a reference.

Then just serialize the list (or whatever object you want) with the following:

using Newtonsoft.Json;

string json = JsonConvert.SerializeObject(listTop10);

Update: you can also add it to your project via the NuGet Package Manager (Tools --> NuGet Package Manager --> Package Manager Console):

PM> Install-Package Newtonsoft.Json

Documentation: Serializing Collections

Solution 3:

There are two common ways of doing that with built-in JSON serializers:

JavaScriptSerializer

var serializer = new JavaScriptSerializer();
return serializer.Serialize(TheList);

DataContractJsonSerializer

var serializer = new DataContractJsonSerializer(TheList.GetType());
using (var stream = new MemoryStream())
{
    serializer.WriteObject(stream, TheList);
    using (var sr = new StreamReader(stream))
    {
        return sr.ReadToEnd();
    }
}

Note, that this option requires definition of a data contract for your class:

[DataContract]
public class MyObjectInJson
{
   [DataMember]
   public long ObjectID {get;set;}
   [DataMember]
   public string ObjectInJson {get;set;}
}

Solution 4:

public static string JSONSerialize<T>(T obj)
        {
            string retVal = String.Empty;
            using (MemoryStream ms = new MemoryStream())
            {
                DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
                serializer.WriteObject(ms, obj);
                var byteArray = ms.ToArray();
                retVal = Encoding.UTF8.GetString(byteArray, 0, byteArray.Length);
            }
            return retVal;
        }