转换为十进制数字并将格式数字转换为小数点后两位

Question

The output from the code below produces a decimal number with 13 digits after decimal mark. I want to round off that number to only 2 digits after decimal mark. I've tried to use the Decimal.Round Method to no avail, apparently I'm not using it right.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace TorrentPirate
{
    class Program
    {
        static void Main(string[] args)
        {

            TimeSpan time = TimeSpan.FromSeconds(1000);

            double downloadTime = time.TotalHours;

            double money = 50;

            double wifeSpending = money * downloadTime;



            Console.WriteLine(Convert.ToDecimal(wifeSpending));

        }
    }
}

Answer 1

As I understand from your comments, you are doing it like this:

Math.Round(wifeSpending, 2);

The Round method does not change the variable that you pass in. It even couldn't if it wanted to because the double value is passed by value (not by reference).

What the Round method does is that it returns a new double that is rounded. Here is what you need to do:

wifeSpending = Math.Round(wifeSpending, 2);