How to declare a class instance as a constant in C#?

Question

I need to implement this:

static class MyStaticClass
{
    public const TimeSpan theTime = new TimeSpan(13, 0, 0);
    public static bool IsTooLate(DateTime          


        

Answer 1

You can use the readonly keyword:

When a field declaration includes a readonly modifier, assignments to the fields introduced by the declaration can only occur as part of the declaration or in a constructor in the same class.

Example (copied from the linked MSDN page):

class Age
{
    readonly int _year;
    Age(int year)
    {
        _year = year;
    }
    void ChangeYear()
    {
        //_year = 1967; // Compile error if uncommented.
    }
}