How can I format a nullable DateTime with ToString()?

Question

How can I convert the nullable DateTime dt2 to a formatted string?

DateTime dt = DateTime.Now;
Console.WriteLine(dt.ToString(\"yyyy-MM-dd hh         


        

Answer 1

RAZOR syntax:

@(myNullableDateTime?.ToString("yyyy-MM-dd") ?? String.Empty)

Answer 2

As others have stated you need to check for null before invoking ToString but to avoid repeating yourself you could create an extension method that does that, something like:

public static class DateTimeExtensions {

  public static string ToStringOrDefault(this DateTime? source, string format, string defaultValue) {
    if (source != null) {
      return source.Value.ToString(format);
    }
    else {
      return String.IsNullOrEmpty(defaultValue) ?  String.Empty : defaultValue;
    }
  }

  public static string ToStringOrDefault(this DateTime? source, string format) {
       return ToStringOrDefault(source, format, null);
  }

}

Which can be invoked like:

DateTime? dt = DateTime.Now;
dt.ToStringOrDefault("yyyy-MM-dd hh:mm:ss");  
dt.ToStringOrDefault("yyyy-MM-dd hh:mm:ss", "n/a");
dt = null;
dt.ToStringOrDefault("yyyy-MM-dd hh:mm:ss", "n/a")  //outputs 'n/a'

Answer 3

Here is Blake's excellent answer as an extension method. Add this to your project and the calls in the question will work as expected.
Meaning it is used like MyNullableDateTime.ToString("dd/MM/yyyy"), with the same output as MyDateTime.ToString("dd/MM/yyyy"), except that the value will be "N/A" if the DateTime is null.

public static string ToString(this DateTime? date, string format)
{
    return date != null ? date.Value.ToString(format) : "N/A";
}

Answer 4

C# 6.0 baby:

dt2?.ToString("dd/MM/yyyy");

Answer 5

What about something as easy as this:

String.Format("{0:dd/MM/yyyy}", d2)

Answer 6

Maybe it is a late answer but may help anyone else.

Simple is:

nullabledatevariable.Value.Date.ToString("d")

or just use any format rather than "d".

Best