ASP.NET MVC JsonResult Date Format

Question

I have a controller action that effectively simply returns a JsonResult of my model. So, in my method I have something like the following:

return new JsonRes         


        

Answer 1

There are quite a bit of answers to handle it client side, but you can change the output server side if you desired.

There are a few ways to approach this, I'll start with the basics. You'll have to subclass the JsonResult class and override the ExecuteResult method. From there you can take a few different approaches to change the serialization.

Approach 1: The default implementation uses the JsonScriptSerializer. If you take a look at the documentation, you can use the RegisterConverters method to add custom JavaScriptConverters. There are a few problems with this though: The JavaScriptConverter serializes to a dictionary, that is it takes an object and serializes to a Json dictionary. In order to make the object serialize to a string it requires a bit of hackery, see post. This particular hack will also escape the string.

public class CustomJsonResult : JsonResult
{
    private const string _dateFormat = "yyyy-MM-dd HH:mm:ss";

    public override void ExecuteResult(ControllerContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("context");
        }

        HttpResponseBase response = context.HttpContext.Response;

        if (!String.IsNullOrEmpty(ContentType))
        {
            response.ContentType = ContentType;
        }
        else
        {
            response.ContentType = "application/json";
        }
        if (ContentEncoding != null)
        {
            response.ContentEncoding = ContentEncoding;
        }
        if (Data != null)
        {
            JavaScriptSerializer serializer = new JavaScriptSerializer();

            // Use your custom JavaScriptConverter subclass here.
            serializer.RegisterConverters(new JavascriptConverter[] { new CustomConverter });

            response.Write(serializer.Serialize(Data));
        }
    }
}

Approach 2 (recommended): The second approach is to start with the overridden JsonResult and go with another Json serializer, in my case the Json.NET serializer. This doesn't require the hackery of approach 1. Here is my implementation of the JsonResult subclass:

public class CustomJsonResult : JsonResult
{
    private const string _dateFormat = "yyyy-MM-dd HH:mm:ss";

    public override void ExecuteResult(ControllerContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("context");
        }

        HttpResponseBase response = context.HttpContext.Response;

        if (!String.IsNullOrEmpty(ContentType))
        {
            response.ContentType = ContentType;
        }
        else
        {
            response.ContentType = "application/json";
        }
        if (ContentEncoding != null)
        {
            response.ContentEncoding = ContentEncoding;
        }
        if (Data != null)
        {
            // Using Json.NET serializer
            var isoConvert = new IsoDateTimeConverter();
            isoConvert.DateTimeFormat = _dateFormat;
            response.Write(JsonConvert.SerializeObject(Data, isoConvert));
        }
    }
}

Usage Example:

[HttpGet]
public ActionResult Index() {
    return new CustomJsonResult { Data = new { users=db.Users.ToList(); } };
}

Additional credits: James Newton-King