How to: Safely Cast from bool? to bool (C# Programming Guide

bool? test = null;
// Other code that may or may not
// give a value to test.
if(!test.HasValue) //check for a value
{
    // Assume that IsInitialized
    // returns either true or false.
    test = IsInitialized();
}
if((bool)test) //now this cast is safe
{
   // Do something.
}

// Source: https://msdn.microsoft.com/en-us/library/bb384091.aspx