用C#写 四舍五入函数(函数版)

适用范围：长整型long(-9223272036854775808 ~  +9223272036854775808)

        //BY: bit.Aipeli 2005-11-07 23:27:23

        private double Round(double v,int x)
        {
            int i;
            long IValue=1;
            double DValue=1;
        
            for (i=1;i<=x;i++)
            {
                IValue=IValue*10;
                DValue=DValue/10;
            }
            long Int=(long)Decimal.Round(Convert.ToDecimal(v*IValue),0);
            double Key=(double)(v/DValue)-Int;
            double Dou=(double)Int/IValue;

            if (Key>=0.5)
            {
                Dou+=DValue;
            }
            return Dou;
        }

本代码在：Windows 2003 && Microsoft Visual Studio .NET 2003 通过