using System;
using System.Collections.Generic;
using System.Text;
namespace ConsoleApplication5
{
    class Program
    {
        static double a(double x)
        {
            if (x - (int)x >= 0.5)
                x = (int)x + 1;
            else
                x = (int)x;
            return x;
        }
        static void Main(string[] args)
        {
            Console.WriteLine("输入金额");
            double x=double.Parse(Console.ReadLine());
            Console.WriteLine("{0}",x);
        }
    }
}

为什么算不出来四舍五入呢？哪有问题呀。。。请指点一下~~