.NET and Silverlight Rounding

    Math.Round(34.5, MidpointRounding.AwayFromZero);   // Now rounds to 35

A little annoying since in all of the applications that I’ve ever written the users expect rounding to match Excel’s and I’ve never needed the default. Worse, in Silverlight you don’t even have the option to change the default when using Math.Round().

So I had to write my own extension that can be used like:

    double myValue = 34.5;

    int myRoundedValue = (int) myValue.RoundCorrect(0);  // rounds to 35

Here is the extension code:

public static class DoubleExtensions

{

    public static double RoundCorrect(this double d, int decimals)

    {

        double multiplier = Math.Pow(10, decimals);

        if (d < 0)

            multiplier *= -1;

        return Math.Floor((d * multiplier) + 0.5) / multiplier;

    }

}

or if you want the code for a normal method it would be

public double RoundCorrect(double d, int decimals)

{

    double multiplier = Math.Pow(10, decimals);

    if (d < 0)

        multiplier *= -1;

    return Math.Floor((d * multiplier) + 0.5) / multiplier;

}