How can I String.Format a TimeSpan object with a custom format in .NET?

Question

What is the recommended way of formatting TimeSpan objects into a string with a custom format?

Answer 1

I wanted to return a string such as "1 day 2 hours 3 minutes" and also take into account if for example days or minuttes are 0 and then not showing them. thanks to John Rasch for his answer which mine is barely an extension of

TimeSpan timeLeft = New Timespan(0, 70, 0);
String.Format("{0}{1}{2}{3}{4}{5}",
    Math.Floor(timeLeft.TotalDays) == 0 ? "" : 
    Math.Floor(timeLeft.TotalDays).ToString() + " ",
    Math.Floor(timeLeft.TotalDays) == 0 ? "" : Math.Floor(timeLeft.TotalDays) == 1 ? "day " : "days ",
    timeLeft.Hours == 0 ? "" : timeLeft.Hours.ToString() + " ",
    timeLeft.Hours == 0 ? "" : timeLeft.Hours == 1 ? "hour " : "hours ",
    timeLeft.Minutes == 0 ? "" : timeLeft.Minutes.ToString() + " ",
    timeLeft.Minutes == 0 ? "" : timeLeft.Minutes == 1 ? "minute " : "minutes ");