我有一些由集合返回的字段

2.4200
2.0044
2.0000

我想要这样的结果

2.42
2.0044
2

我试过用String。格式,但它返回2.0000,并将其设置为N0也会四舍五入其他值。


当前回答

这是我写的一个扩展方法,如果它是最后一个字符(在0被删除之后),它也会删除点或逗号:

public static string RemoveZeroTail(this decimal num)
{
    var result = num.ToString().TrimEnd(new char[] { '0' });
    if (result[result.Length - 1].ToString() == "." || result[result.Length - 1].ToString() == ",")
    {
        return result.Substring(0, result.Length - 1);
    }
    else
    {
        return result;
    }
}

其他回答

一个非常低级的方法,但我相信这将是最高效的方法,只使用快速整数计算(没有缓慢的字符串解析和区域性敏感的方法):

public static decimal Normalize(this decimal d)
{
    int[] bits = decimal.GetBits(d);

    int sign = bits[3] & (1 << 31);
    int exp = (bits[3] >> 16) & 0x1f;

    uint a = (uint)bits[2]; // Top bits
    uint b = (uint)bits[1]; // Middle bits
    uint c = (uint)bits[0]; // Bottom bits

    while (exp > 0 && ((a % 5) * 6 + (b % 5) * 6 + c) % 10 == 0)
    {
        uint r;
        a = DivideBy10((uint)0, a, out r);
        b = DivideBy10(r, b, out r);
        c = DivideBy10(r, c, out r);
        exp--;
    }

    bits[0] = (int)c;
    bits[1] = (int)b;
    bits[2] = (int)a;
    bits[3] = (exp << 16) | sign;
    return new decimal(bits);
}

private static uint DivideBy10(uint highBits, uint lowBits, out uint remainder)
{
    ulong total = highBits;
    total <<= 32;
    total = total | (ulong)lowBits;

    remainder = (uint)(total % 10L);
    return (uint)(total / 10L);
}

在我看来,使用自定义数字格式字符串更安全。

decimal d = 0.00000000000010000000000m;
string custom = d.ToString("0.#########################");
// gives: 0,0000000000001
string general = d.ToString("G29");
// gives: 1E-13

要从字符串变量dateTicks中删除后面的零,请使用

返回新的字符串(dateTicks.Take(dateTicks.LastIndexOf(dateTicks.Last(v => v != '0')) + 1)。ToArray());

我从http://dobrzanski.net/2009/05/14/c-decimaltostring-and-how-to-get-rid-of-trailing-zeros/上找到了一个优雅的解决方案

基本上

decimal v=2.4200M;

v.ToString("#.######"); // Will return 2.42. The number of # is how many decimal digits you support.

尝试做更友好的解决方案DecimalToString (https://stackoverflow.com/a/34486763/3852139):

private static decimal Trim(this decimal value)
{
    var s = value.ToString(CultureInfo.InvariantCulture);
    return s.Contains(CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator)
        ? Decimal.Parse(s.TrimEnd('0'), CultureInfo.InvariantCulture)
        : value;
}

private static decimal? Trim(this decimal? value)
{
    return value.HasValue ? (decimal?) value.Value.Trim() : null;
}

private static void Main(string[] args)
{
    Console.WriteLine("=>{0}", 1.0000m.Trim());
    Console.WriteLine("=>{0}", 1.000000023000m.Trim());
    Console.WriteLine("=>{0}", ((decimal?) 1.000000023000m).Trim());
    Console.WriteLine("=>{0}", ((decimal?) null).Trim());
}

输出:

=>1
=>1.000000023
=>1.000000023
=>