async/await

async_await

 class Program
    {
        public static void Main()
        {
            Console.WriteLine("Hey David, How much is 98745 divided by 7?");

            Task<int> david = ThinkAboutIt();

            Console.WriteLine("While he thinks, lets chat about the weather for a bit.");
            Console.WriteLine("Do you think it's going to rain tomorrow?");
            Console.WriteLine("No, I think it should be sunny.");

            david.Wait();
            var davidsAnswer = david.Result;

            Console.WriteLine($"David: {davidsAnswer}");

            Console.ReadKey();
        }

        private static async Task<int> ThinkAboutIt()
        {
            await ReadTheManual();

            Console.WriteLine("Think I got it.");

            return (98745 / 7);
        }

        private static async Task ReadTheManual()
        {
            string file = @"D:\HowToCalc.txt";

            Console.WriteLine("Reading a manual.");
            
            using (StreamReader reader = new StreamReader(file))
            {
                string text = await reader.ReadToEndAsync();
            }

            Console.WriteLine("Done.");
        }
    }