C#中取小数有效数字采用round函数，遇到0.499995就是0.49，而我需要0.50

如题。C#中取小数有效数字采用round函数，遇到0.499995就是0.49，而我需要0.50

 using System;

public class Test
{
    public static double myround(double d)
    {
        return (int)(d * 100 + 0.5) / 100.0;
    }
    public static void Main()
    {
        // your code goes here
        double d1 = 0.499995;
        double d2 = 0.494;
        double d3 = 0.495;
        double d4 = 0.496;
        Console.WriteLine("{0:0.00} {1:0.00} {2:0.00} {3:0.00}", myround(d1), myround(d2), myround(d3), myround(d4));
    }
}

0.50 0.49 0.50 0.50

             double x = 0.499995;
            textBox1.Text += float.Parse(x.ToString()).ToString("f2");

结果是0.50

decimal Round(decimal d, int decimals, MidpointRounding mode)