Network Programming in .NET

When you try to serialize an object that contains an IPAddress, you get the error message Error getting value from ‘ScopeId’ on ‘System.Net.IPAddress’.

So, you have to override how Json.NET (Newtonsoft) serializes this type. Which means you create a class that converts a this problematic type to and from a string youself.

public class IPConverter : JsonConverter<IPAddress>
{
public override void WriteJson(JsonWriter writer, IPAddress value, JsonSerializer serializer)
{
writer.WriteValue(value.ToString());
}

public override IPAddress ReadJson(JsonReader reader, Type objectType, IPAddress existingValue, bool hasExistingValue, JsonSerializer serializer)
{
var s = (string)reader.Value;
return IPAddress.Parse(s);
}
}

Now, you pass this class into JsonSerializerSettings, like so;

var jsonSettings = new JsonSerializerSettings();
jsonSettings.Converters.Add(new IPConverter());
var json = JsonConvert.SerializeObject(result, Formatting.Indented, jsonSettings);

Where results is the object that contains the IP address.