Serialize/Deserializar Datetime

Question

I am saving in text file a serialized object that contains only fields of type Datetime, however, the date is saving in the wrong way.

I will demonstrate with an example what I am doing.

My Databaseviewmodel object has two Datetime-like fields

[Serializable]
public class DataBaseViewModel
{
    public DateTime ultimaAtualizacaoTfs { get; set; }
    public DateTime ultimaAtualizacaoSis { get; set; }
}

I add values to my object

var datasBase = new DatasBaseViewModel();
datasBase.ultimaAtualizacaoSis = new DateTime(2015, 11, 9, 15, 10, 10);
datasBase.ultimaAtualizacaoTfs = new DateTime(2015, 11, 9, 15, 11, 11);

So save the object serialized in text

using (Stream stream = File.Open(_pathToDatasBase, FileMode.Create))
using (StreamWriter streamWriter = new StreamWriter(stream))
{
    streamWriter.WriteLine(new JavaScriptSerializer().Serialize(dataBase));
}

Another time, I will read the contents of my text file.

var datasBase = new DataBaseViewModel();
using (Stream stream = File.Open(_pathToDatasBase, FileMode.Open))
using (StreamReader streamReader = new StreamReader(stream))
{
    datasBase = new JavaScriptSerializer().Deserialize<DataBaseViewModel>(streamReader.ReadToEnd());
}

After reading and deserializar, my object is with the incorrect date, different from what I saved.

In that case, I saved the dates 09/11/2015 15:10:10 and 09/11/2015 15:11:11 and in the deserialized object I have the dates 09/11/2015 17:10:10 and 09/11/2015 17:11:11.

The text file with the serialized object is saved this way:

{"ultimaAtualizacaoTfs":"\/Date(1447089071000)\/","ultimaAtualizacaoSis":"\/Date(1447089010000)\/"}

Answer 1

If you change the type of the two properties of your class to DateTimeOffset you will be in debug that at the end of the value it will be with -2, when decenrialize the object and look at the same value in the new class the value will be 0, are exactly the two hours that are increasing.

Just change the way you create the date it will work normal.

            datasBase.ultimaAtualizacaoTfs = new DateTime(2015, 11, 9, 15, 10, 10,  DateTimeKind.Utc);
            datasBase.ultimaAtualizacaoSis = new DateTime(2015, 11, 9, 15, 11, 11, DateTimeKind.Utc

You will also notice that the serialized value is different now because it is setting the date to the correct value.

No need to change the value of properties to DateTimeOffset, only if you are curious to see the difference I spoke of. It works normally with DateTime

            var dataCerta = new DateTime();
            var dataErrada = new DateTime();

            dataCerta = new DateTime(2015, 11, 9, 15, 10, 10,  DateTimeKind.Utc);
            dataErrada = new DateTime(2015, 11, 9, 15, 10, 10);


            var dataCertaSerializada = new JavaScriptSerializer().Serialize(dataCerta);
            var dataErradaSerializada = new JavaScriptSerializer().Serialize(dataErrada);

            Console.Write(String.Format("Valor serializado da data certa:  {0} \n", dataCertaSerializada.ToString()));
            Console.Write(String.Format("Valor serializado da data errada: {0} \n", dataErradaSerializada.ToString()));

            var dataCertaDecerializada = new JavaScriptSerializer().Deserialize<DateTime>(dataCertaSerializada);
            var dataErradaDecerializada = new JavaScriptSerializer().Deserialize<DateTime>(dataErradaSerializada);

            Console.Write(String.Format("Valor Deserializado da data certa:  {0} \n", dataCertaDecerializada.ToString()));
            Console.Write(String.Format("Valor Deserializado da data errada: {0} \n", dataErradaDecerializada.ToString()));