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I'm using Newtonsoft JSON Serializer and it's great and super fast but I'd like to do a bit more with it. I'm not sure it's possible as all the search I've done comes up to nothing. What I would like is to be able to truncate empty time, so when it's display 2014-01-01 00:00:00.000 I just want 2014-01-01 at the end, so basically cut the entire time when they're all zeros. For now I use this piece of code:

DataTable dt = loadData();// encode the string with Newton JSON.Net string output = JsonConvert.SerializeObject(dt,    new JsonSerializerSettings    {        ReferenceLoopHandling = ReferenceLoopHandling.Ignore,        Formatting = Newtonsoft.Json.Formatting.None,        DateFormatString = "yyyy-MM-dd HH:mm:ss"    });

Is there a way to format these dates without the time (only when they are all zeros) without affecting the performance?

 

Best How To :

                

You can do this with a custom JsonConverter:

class CustomDateConverter : JsonConverter{    public override bool CanConvert(Type objectType)    {        return (objectType == typeof(DateTime));    }    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)    {        DateTime date = (DateTime)value;        string format = "yyyy-MM-dd HH:mm:ss";        if (date.Hour == 0 &&             date.Minute == 0 &&             date.Second == 0 &&             date.Millisecond == 0)        {            format = "yyyy-MM-dd";        }        writer.WriteValue(date.ToString(format));    }    public override bool CanRead    {        get { return false; }    }    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)    {        throw new NotImplementedException();    }}

Demo:

class Program{    static void Main(string[] args)    {        List
     
       dates = new List
      
               {            DateTime.Now,            DateTime.Today        };        JsonSerializerSettings settings = new JsonSerializerSettings        {            ReferenceLoopHandling = ReferenceLoopHandling.Ignore,            Formatting = Newtonsoft.Json.Formatting.None,            Converters = new List
       
         { new CustomDateConverter() }        };        string json = JsonConvert.SerializeObject(dates, settings);        Console.WriteLine(json);    }}
       
      
     

Output:

["2014-06-11 11:56:28","2014-06-11"]