http://pt.stackoverflow.com/q/16185/101 | C# Online Compiler

http://pt.stackoverflow.com/q/16185/101 by bigown

using System;
using static System.Console;
using static System.Math;

public class Program {
    public static void Main() {
        WriteLine("Decimal");
        for (var valor = -1M; valor <= 1M; valor += 0.05M) WriteLine("{0:N1} => {1:N1}", valor, valor.RoundMidPoint());
        WriteLine("Double");
        for (var valor = -1.0; valor <= 1.0; valor += 0.05) WriteLine("{0:N1} => {1:N1}", valor, valor.RoundMidPoint());
    }
}

public static class RoundUtil {
    public static Decimal RoundMidPoint(this Decimal value) => Sign(value) * Ceiling(Abs(value) * 2) / 2;

    public static double RoundMidPoint(this double value) => Sign(value) * Ceiling(Abs(value) * 2) / 2;
}

​x
 
using System;
using static System.Console;
using static System.Math;
​
public class Program {
    public static void Main() {
        WriteLine("Decimal");
        for (var valor = -1M; valor <= 1M; valor += 0.05M) WriteLine("{0:N1} => {1:N1}", valor, valor.RoundMidPoint());
        WriteLine("Double");
        for (var valor = -1.0; valor <= 1.0; valor += 0.05) WriteLine("{0:N1} => {1:N1}", valor, valor.RoundMidPoint());
    }
}
​
public static class RoundUtil {
    public static Decimal RoundMidPoint(this Decimal value) => Sign(value) * Ceiling(Abs(value) * 2) / 2;
​
    public static double RoundMidPoint(this double value) => Sign(value) * Ceiling(Abs(value) * 2) / 2;
}

Decimal
-1.0 => -1.0
-1.0 => -1.0
-0.9 => -1.0
-0.9 => -1.0
-0.8 => -1.0
-0.8 => -1.0
-0.7 => -1.0
-0.7 => -1.0
-0.6 => -1.0
-0.6 => -1.0
-0.5 => -0.5
-0.5 => -0.5
-0.4 => -0.5
-0.4 => -0.5
-0.3 => -0.5
-0.3 => -0.5
-0.2 => -0.5
-0.2 => -0.5
-0.1 => -0.5
-0.1 => -0.5
0.0 => 0.0
0.1 => 0.5
0.1 => 0.5
0.2 => 0.5
0.2 => 0.5
0.3 => 0.5
0.3 => 0.5
0.4 => 0.5
0.4 => 0.5
0.5 => 0.5
0.5 => 0.5
0.6 => 1.0
0.6 => 1.0
0.7 => 1.0
0.7 => 1.0
0.8 => 1.0
0.8 => 1.0
0.9 => 1.0
0.9 => 1.0
1.0 => 1.0
1.0 => 1.0
Double
-1.0 => -1.0
-0.9 => -1.0
-0.9 => -1.0
-0.8 => -1.0
-0.8 => -1.0
-0.7 => -1.0
-0.7 => -1.0
-0.6 => -1.0
-0.6 => -1.0
-0.5 => -1.0
-0.5 => -0.5
-0.4 => -0.5
-0.4 => -0.5
-0.3 => -0.5
-0.3 => -0.5
-0.2 => -0.5
-0.2 => -0.5
-0.1 => -0.5
-0.1 => -0.5
-0.0 => -0.5
0.0 => 0.5
0.1 => 0.5
0.1 => 0.5
0.2 => 0.5
0.2 => 0.5
0.3 => 0.5
0.3 => 0.5
0.4 => 0.5
0.4 => 0.5
0.5 => 0.5
0.5 => 1.0
0.6 => 1.0
0.6 => 1.0
0.7 => 1.0
0.7 => 1.0
0.8 => 1.0
0.8 => 1.0
0.9 => 1.0
0.9 => 1.0
1.0 => 1.0

Cached Result
Last Run:	6:34:13 pm
Compile:	0.007s
Execute:	0.06s
Memory:	3.09Mb
CPU:	0.067s

View IL Code