Rounding double values in C#

Question

I want a rounding method on double values in C#. It needs to be able to round a double value to any rounding precision value. My code on hand looks like:

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Answer 1

The examples using decimal casting provided in Jimmy's answer don't answer the question, since they do not show how to round a double value to any rounding precision value as requested. I believe the correct answer using decimal casting is the following:

    public static double RoundI(double number, double roundingInterval)
    {
        return (double)((decimal)roundingInterval * Math.Round((decimal)number / (decimal)roundingInterval, MidpointRounding.AwayFromZero));
    }

Because it uses decimal casting, this solution is subject to the casting errors mentioned by Jeppe Stig Nielsen in his comment to Jimmy's answer.

Also, note that I specified MidpointRounding.AwayFromZero, since that is consistent with the requester's specification that RoundI(1.2345, 0.001) should give 1.235.