How to render a DateTime in a specific format in ASP.NET MVC 3?

Question

If I have in my model class a property of type DateTime how can I render it in a specific format - for example in the format which ToLongDateString() returns?

I have tried this...

@Html.DisplayFor(modelItem => item.MyDateTime.ToLongDateString())

...which throws an exception because the expression must point to a property or field. And this...

@{var val = item.MyDateTime.ToLongDateString();
  Html.DisplayFor(modelItem => val);
}

...which doesn't throw an exception, but the rendered output is empty (although val contains the expected value, as I could see in the debugger).

Thanks for tips in advance!

Edit

ToLongDateString is only an example. What I actually want to use instead of ToLongDateString is a custom extension method of DateTime and DateTime?:

public static string FormatDateTimeHideMidNight(this DateTime dateTime)
{
    if (dateTime.TimeOfDay == TimeSpan.Zero)
        return dateTime.ToString("d");
    else
        return dateTime.ToString("g");
}

public static string FormatDateTimeHideMidNight(this DateTime? dateTime)
{
    if (dateTime.HasValue)
        return dateTime.Value.FormatDateTimeHideMidNight();
    else
        return "";
}

So, I think I cannot use the DisplayFormat attribute and DataFormatString parameter on the ViewModel properties.

Answer 1

You could decorate your view model property with the [DisplayFormat] attribute:

[DisplayFormat(DataFormatString = "{0:dd/MM/yyyy}", 
               ApplyFormatInEditMode = true)]
public DateTime MyDateTime { get; set; }

and in your view:

@Html.EditorFor(x => x.MyDate)

or, for displaying the value,

@Html.DisplayFor(x => x.MyDate)

Another possibility, which I don't recommend, is to use a weakly typed helper:

@Html.TextBox("MyDate", Model.MyDate.ToLongDateString())

Answer 2

If all you want to do is display the date with a specific format, just call:

@String.Format(myFormat, Model.MyDateTime)

Using @Html.DisplayFor(...) is just extra work unless you are specifying a template, or need to use something that is built on templates, like iterating an IEnumerable<T>. Creating a template is simple enough, and can provide a lot of flexibility too. Create a folder in your views folder for the current controller (or shared views folder) called DisplayTemplates. Inside that folder, add a partial view with the model type you want to build the template for. In this case I added /Views/Shared/DisplayTemplates and added a partial view called ShortDateTime.cshtml.

@model System.DateTime

@Model.ToShortDateString()

And now you can call that template with the following line:

@Html.DisplayFor(m => m.MyDateTime, "ShortDateTime")