Decimal类型截取保留N位小数向上取, Decimal类型截取保留N位小数并且不进行四舍五入操作

public class DecimalHelper
{
/// <summary>
/// Decimal类型截取保留N位小数并且不进行四舍五入操作
/// </summary>
/// <param name="d"></param>
/// <param name="n"></param>
/// <returns></returns>
public static decimal CutDecimalWithN(decimal d, int n)
{
string strDecimal = d.ToString();
int index = strDecimal.IndexOf(".");
if (index == -1 || strDecimal.Length < index + n + 1)
{
strDecimal = string.Format("{0:F" + n + "}", d);
}
else
{
int length = index;
if (n != 0)
{
length = index + n + 1;
}
strDecimal = strDecimal.Substring(0, length);
}
return Decimal.Parse(strDecimal);
} /// <summary>
/// Decimal类型截取保留N位小数向上取
/// </summary>
/// <param name="d"></param>
/// <param name="n"></param>
/// <returns></returns>
public static decimal Ceiling(decimal d, int n)
{
decimal t = decimal.Parse(Math.Pow(10, n).ToString());
d = Math.Ceiling(t * d);
return d / t;
}
}

class Program
{
static void Main(string[] args)
{
Console.WriteLine();
decimal Dec = 12.12345M;
for (int i = 0; i < 10; i++)
{
Console.WriteLine($"{Dec} 保留{i} 位小数不进行四舍五入操作：" + DecimalHelper.CutDecimalWithN(Dec, i));
}
Console.WriteLine();
for (int i = 0; i < 10; i++)
{
Console.WriteLine($"{Dec} 保留{i} 位小数向上取整操作：" + DecimalHelper.Ceiling(Dec, i));
}
Console.Read();
}
}