Proper Way to Convert JSON Date to .NET DateTime During Deserialization

Question

I have a javascript function that calls an MVC controller with JSON data:

var specsAsJson = JSON.stringify(specs);
$.post('/Home/Save', { jsonData: specsAsJson });

On the server side, within the controller, I can't seem to get past this error:

/Date(1347992529530)/ is not a valid value for DateTime.

That exception happens when I call Deserialize() (third line in method below):

    public ActionResult Save(string jsonData)
    {
        var serializer = new JavaScriptSerializer();
        serializer.RegisterConverters(new[] { new TimeSpanJsonConverter() });
        var specs = serializer.Deserialize<List<EquipmentSpecWithParameterlessConstructor>>(jsonData);

        return View("Index", _allTrackerJobs);
    }

I've been doing some googling, and the above code is my latest attempt to make this work (using the TimeSpanJsonConverter from here). Other approaches show sending only a date to the server, but I have a list of objects that have dates as some properties.

Is there an elegant, generally-accepted approach to solving this, or do we still need some kind of ugly work-around? What's the right way to resolve this?

=================== End of original question ===================

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Edit - SOLVED by serializing using JsonConvert

See my answer below (not the crappy work-around in this question).

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Edit - Crappy work-around

I created a DTO with the exact same fields as the domain object, except that I made the date fields strings so they would deserialize. Now that I can deserialize it, I'll work on getting the dates into a valid format so I can create domain objects from my DTOs.

public class EquipmentSpecDto
{
    public string StartTime { get; set; }
    public string EndTime { get; set; }
    // more properties here
}

And I simply just used the DTO for the deserialization:

var specs = serializer.Deserialize<List<EquipmentSpecDto>>(jsonData);

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Edit 2 - Converting JavaScript Dates to .NET

For completeness, and in the hopes that I save someone else an hour, this is how I was able to convert the javascript dates:

    foreach (EquipmentSpecDto specDto in specDtos)
    {
        // JavaScript uses the unix epoch of 1/1/1970. Note, it's important to call ToLocalTime()
        // after doing the time conversion, otherwise we'd have to deal with daylight savings hooey.
        DateTime unixEpoch       = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
        Double startMilliseconds = Convert.ToDouble(specDto.StartTime.Substring(6, 13));
        Double endMilliseconds   = Convert.ToDouble(specDto.EndTime.Substring(6, 13));
        DateTime startTime       = unixEpoch.AddMilliseconds(startMilliseconds).ToLocalTime();
        DateTime endTime         = unixEpoch.AddMilliseconds(endMilliseconds).ToLocalTime();
        EquipmentSpec spec       = new EquipmentSpec(startTime, endTime, specDto.Equipment);

        specs.Add(spec);
    }

Answer 1

I found a simple answer. In my javascript, I was serializing the data using the JavaScriptSerializer. After much googling, I found this article that shows how to serialize using JsonConvert that causes a more .NET-friendly DateTime to be used.

Old:

var specs = @Html.Raw(new System.Web.Script.Serialization.JavaScriptSerializer().Serialize(ViewBag.JobSpecEquipment))

Dates look like this: Date(1348017917565)

New:

var specs = @Html.Raw(Newtonsoft.Json.JsonConvert.SerializeObject(ViewBag.JobSpecEquipment));

Dates look like this: 2012-09-18T21:27:31.1285861-04:00

So the problem was really how I was serializing in the first place. Once I used JsonConvert, deserialization on the back end simply worked.

Answer 2

I found this piece of code on the internet. It worked like a charm for me...

function customJSONstringify(obj) {
    return JSON.stringify(obj).replace(/\/Date/g, "\\\/Date").replace(/\)\//g, "\)\\\/")
}