Question

Can CultureInfo.CurrentCulture ever be null?

A null value would crash my program, which I don’t want. So I’m asking, to be safe, do I need to do?

var culture = CultureInfo.CurrentCulture ?? CultureInfo.InvariantCulture

Answer 1

It definitely looks like it’s guaranteed to be non-null:

The culture is a property of the executing thread. This read-only
property is equivalent to retrieving the CultureInfo object returned
by the Thread.CurrentCulture property.

Thread.CurrentCulture throws an exception if you try to set it to null, so it’s logical to assume that having a non-null value is an invariant.

Apart from this, CultureInfo.CurrentCulture gives the algorithm that determines its initial value:

How a Thread’s Culture Is Determined

When a thread is started, its culture is initially determined as
follows:

• By retrieving the culture that is specified by the DefaultThreadCurrentCulture property in the application domain in
  which the thread is executing, if the property value is not null.

• By calling the Windows GetUserDefaultLocaleName function.

Again, this doesn’t leave open the option of a null value.