Adventures in Code: July 2017

Friday, July 21, 2017

Colorful serialization

I was writing some code to serialize a C# class to JSON and needed to export a System.Drawing.Color field as a hex string. Thankfully it's easy to customize the output using Json.NET. I created the following custom converter to save colors as hex strings (like #FFF0B6)

public class ColorHexConverter : JsonConverter {
 
 public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) {
  var color = (Color)value;
  var hexString = color.IsEmpty ? string.Empty : string.Concat("#", (color.ToArgb() & 0x00FFFFFF).ToString("X6");
  writer.WriteValue(hexString);
 }
 
 public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) {
  var hexString = reader.Value.ToString();
  if (hexString == null || !hexString.StartsWith("#")) return Color.Empty;
  return ColorTranslator.FromHtml(hexString);
 }
 
 public override bool CanConvert(Type objectType) {
  return objectType == typeof(Color);
 }
}

And example usage:

[JsonConverter(typeof(ColorHexConverter))]
public Color BackgroundColor;