using System;

using System.Drawing;

public class Program

{

    public static void Main()

    {

        //set HeightOfField, RowShowing

        double HeightOfField = 0.535;

        double RowShowing = 21;

        double HeightDetail = 0;            

​

        HeightDetail = RowShowing * HeightOfField;

        HeightOfField = Program.CmToPixel(HeightOfField);

        HeightDetail = Program.CmToPixel(HeightDetail);

        Console.WriteLine(HeightDetail);        

    }

    public static double CmToPixel(double cm = 0)

        {

            double pixel = -1;

            Graphics g = Graphics.FromImage(new Bitmap(1, 1));

            pixel = cm * g.DpiY / 2.54d;

            return pixel;

        }

}