如何从具有Datetime属性的对象的IEnumerble列表中的Ajax调用正确序列化Datetime

Question

So I have a IEnumerable list of an object in my View as my model. The object has fields such as strings, ints, bools, and Datetime. I want to serialize that list but the issue is that everything is done correctly except for the Datetime and for some reason it serializes into an incorrect number of ticks resulting in the wrong date when I print it out in my Controller. So I have a variety of dates either June or July 2019 and they all become 01/00/1900. This is being used to export DataTable entries into an Excel sheet.

I have tried iterating through the IEnumerable list with several methods but none work in getting access to the datetime property properly so I cannot just make a second list of those date times.

$("#btnExport").on("click", function () {
      var modelData = '@Html.Raw(Json.Encode(Model))';
      $.ajax({
            type: "POST",
            url: '@Url.Action("ExportTransactionsInExcel", "Gatelog")',
            contentType: "application/json; charset=utf-8",
            data: modelData,
            success: function (result) {
            },
            error: function (obj) {
               alert("fail");
            }
      });
});

So some of the ticks are... Date(1561262400000) Date(1563854400000) Date(1561867200000) Date(1564459200000) I want to be able to encode the list and still have it return the correct dates

Answer 1

So I think it has already been covered that javascript Date using milliseconds from the UTC epoch 1/1/1970 where C# uses 100 nanosecond ticks from 01/01/0001 . There are two solid options for dealing with this. The first would be to create your own JsonConverter and handle the logic there.

The approach I've chosen to display is a bit simpler. Instead of deserializing directly to a DateTime object, lets deserialize to a long variable instead. Then, we can add a DateTime variable with a custom getter that will handle assignment for you.

public class Model
{
    public long time {get;set;}

    public DateTime datetime 
    {
       get
       {
           return new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)
              .AddMilliseconds(time)
              .ToLocalTime();
       }
    }   
 }

Just make sure that the figure coming in deserializes to the long value and then in your C# code only reference the DateTime value

Answer 2

I ended up just making a new model and creating a JS object that matches those models fields exactly. Then I passed the parameters into the new object and called ajax on it. I re-ran the query from the controller which allowed me to still get the parameters I need and it would perform faster if the list got really large versus doing it all front end.