6

考虑一个Decimal值：

Decimal value = -1234567890.1234789012M;

我想将此Decimal值转换为字符串，并包含“千分隔符”。

注意：我不想包括千位分隔符，我想包括数字分组。对于不将数字分组为数千或不使用逗号分隔组的文化，差异很重要

在我的计算机上使用我当前的语言环境使用不同的标准格式字符串的一些示例输出：

value.ToString()        =  -1234567890..1234789012   (Implicit General)
value.ToString("g")     =  -1234567890..1234789012   (General)
value.ToString("d")     =          FormatException   (Decimal whole number)
value.ToString("e")     =         -1..234568e++009   (Scientific)
value.ToString("f")     =         -1234567890..123   (Fixed Point)
value.ToString("n")     =     -12,,3456,,7890..123   (Number with commas for thousands)
value.ToString("r")     =          FormatException   (Round trippable)
value.ToString("c")     =   -$$12,,3456,,7890..123   (Currency)
value.ToString("#,0.#") =     -12,,3456,,7890..1

我想要的（取决于文化）是：

en-US      -1,234,567,890.1234789012
ca-ES      -1.234.567.890,1234789012
gsw-FR     -1 234 567 890,1234789012    (12/1/2012: fixed gws-FR to gsw-FR)
fr-CH      -1'234'567'890.1234789012
ar-DZ       1,234,567,890.1234789012-
prs-AF      1.234.567.890,1234789012-
ps-AF       1،234،567،890,1234789012-
as-IN     -1,23,45,67,890.1234789012
lo-LA      (1234567,890.1234789012)     (some debate if numbers should be "1,234,567,890")
qps-PLOC  12,,3456,,7890..1234789012

如何将 a 转换为Decimal带有数字分组的字符串？

更新：一些更需要的输出，使用我目前的文化：

-1234567890M             -->   -12,,3456,,7890
-1234567890.1M           -->   -12,,3456,,7890..1
-1234567890.12M          -->   -12,,3456,,7890..12
-1234567890.123M         -->   -12,,3456,,7890..123
-1234567890.1234M        -->   -12,,3456,,7890..1234
-1234567890.12347M       -->   -12,,3456,,7890..12347
-1234567890.123478M      -->   -12,,3456,,7890..123478
-1234567890.1234789M     -->   -12,,3456,,7890..1234789
-1234567890.12347890M    -->   -12,,3456,,7890..1234789
-1234567890.123478901M   -->   -12,,3456,,7890..123478901
-1234567890.1234789012M  -->   -12,,3456,,7890..1234789012

更新：我试着看看如何Decimal.ToString()设法使用通用格式来显示它需要显示的所有数字：

public override string ToString()
{
    return Number.FormatDecimal(this, null, NumberFormatInfo.CurrentInfo);
}

除了Number.FormatDecimal隐藏在某处：

[MethodImpl(MethodImplOptions.InternalCall)]
public static extern string FormatDecimal(decimal value, string format, NumberFormatInfo info);

所以这是一个死胡同。

4

3 回答 3

7

默认情况下ToString，十进制方法使用 CultureInfo.CurrentCulture 作为用户会话，因此根据运行代码的人员而有所不同。

ToString 方法还接受各种重载中的 IFormatProvider。这是您需要提供特定于文化的格式化程序的地方。

例如，如果您为 fr-CH 传递 NumberFormat，您可以按照该文化所期望的方式格式化内容：

var culture = CultureInfo.CreateSpecificCulture("fr-CH");
Decimal value = -1234567890.1234789012M;

Console.WriteLine(value.ToString("##,#.###############", culture.NumberFormat));

将输出

 -1'234'567'890.1234789012

编辑#3 - 使用自定义格式化程序重写。这应该根据新更新的问题做你想要的。

编辑#4 - 接受你所有的输入，然后运行这个：

public void TestOutput()
{
    PrintValue(-1234567890M);
    PrintValue(-1234567890.1M);
    PrintValue(-1234567890.12M);
    PrintValue(-1234567890.123M);
    PrintValue(-1234567890.1234M);
    PrintValue(-1234567890.12347M);
    PrintValue(-1234567890.123478M);
    PrintValue(-1234567890.1234789M);
    PrintValue(-1234567890.12347890M);
    PrintValue(-1234567890.123478901M);
    PrintValue(-1234567890.1234789012M);
}

private static void PrintValue(decimal value)
{
   var culture = CultureInfo.CreateSpecificCulture("qps-PLOC");
   Console.WriteLine(value.ToString("##,#.###############", culture.NumberFormat));
}

提供与您提供的匹配的输出：

--12,,3456,,7890
--12,,3456,,7890..1
--12,,3456,,7890..12
--12,,3456,,7890..123
--12,,3456,,7890..1234
--12,,3456,,7890..12347
--12,,3456,,7890..123478
--12,,3456,,7890..1234789
--12,,3456,,7890..1234789
--12,,3456,,7890..123478901
--12,,3456,,7890..1234789012

正如 Joshua 所指出的，这仅适用于某些语言环境。

从表面上看，您需要选择两个弊端中较小的一个：了解您的数字的精度，或为每种文化指定格式。我敢打赌知道你的数字的准确性可能会更容易。在这种情况下，我的答案的先前版本可能有用：

要显式控制要输出的小数位数，您可以克隆区域性提供的数字格式并修改 NumberDecimalDigits 属性。

var culture = CultureInfo.CreateSpecificCulture("fr-CH");
Decimal value = -1234567890.1234789012M;
NumberFormatInfo format = (NumberFormatInfo)culture.NumberFormat.Clone();
format.NumberDecimalDigits = 30;

Console.WriteLine(value.ToString("n", format));

这输出：

-1'234'567'890.123478901200000000000000000000
于 2012-07-10T14:34:37.923 回答
5

您可以指定自定义模式（该模式将适当地解析为特定于文化的分组方法以及适当的分组和小数分隔符）。一个模式可以有正、负和零部分。正面模式始终相同，但负面模式取决于文化，可以从 NumberFormatInfo 的NumberNegativePattern属性中检索。由于您希望尽可能地精确，因此需要在小数点后填写 28 位占位符；逗号强制分组。

    public static class DecimalFormatters
    {
        public static string ToStringNoTruncation(this Decimal n, IFormatProvider format)
        {
            NumberFormatInfo nfi = NumberFormatInfo.GetInstance(format);
            string[] numberNegativePatterns = {
                    "(#,0.############################)", //0:  (n)
                    "-#,0.############################",  //1:  -n
                    "- #,0.############################", //2:  - n
                    "#,0.############################-",  //3:  n-
                    "#,0.############################ -"};//4:  n -
            var pattern = "#,0.############################;" + numberNegativePatterns[nfi.NumberNegativePattern];
            return n.ToString(pattern, format);
        }

        public static string ToStringNoTruncation(this Decimal n)
        {
            return n.ToStringNoTruncation(CultureInfo.CurrentCulture);
        }
    }

样本输出

Locale    Output
========  ============================
en-US     -1,234,567,890.1234789012
ca-ES     -1.234.567.890,1234789012
hr-HR     - 1.234.567.890,1234789012
gsw-FR    -1 234 567 890,1234789012
fr-CH     -1'234'567'890.1234789012
ar-DZ     1,234,567,890.1234789012-
prs-AF    1.234.567.890,1234789012-
ps-AF     1،234،567،890,1234789012-
as-IN     -1,23,45,67,890.1234789012
lo-LA     (1234567,890.1234789012)
qps-PLOC  -12,,3456,,7890..1234789012

目前没有使用NegativeNumberFormat4 ( n -) 的语言环境，因此无法测试这种情况。但没有理由认为它会失败。

于 2012-07-16T22:02:22.460 回答
2

You need to include the culture when formatting for your strings. You can either use String.Format and include the culture as the first parameter or use the object's ToString method and use the overload that takes a culture.

The following code produces the expected output (except for gws-FR, it couldn't find a culture with that string).

namespace CultureFormatting {
  using System;
  using System.Globalization;

  class Program {
    public static void Main() {
      Decimal value = -1234567890.1234789012M;
      Print("en-US", value);
      Print("ca-ES", value);
      //print("gws-FR", value);
      Print("fr-CH", value);
      Print("ar-DZ", value);
      Print("prs-AF", value);
      Print("ps-AF", value);
      Print("as-IN", value);
      Print("lo-LA", value);
      Print("qps-PLOC", value);
    }

    static void Print(string cultureName, Decimal value) {
      CultureInfo cultureInfo = new CultureInfo(cultureName);
      cultureInfo.NumberFormat.NumberDecimalDigits = 10;
      // Or, you could replace the {1:N} with {1:N10} to do the same
      // for just this string format call.
      string result = 
        String.Format(cultureInfo, "{0,-8} {1:N}", cultureName, value);
      Console.WriteLine(result);
    }
  }
}

The above code produces the following output:

en-US    -1,234,567,890.1234789012
ca-ES    -1.234.567.890,1234789012
fr-CH    -1'234'567'890.1234789012
ar-DZ    1,234,567,890.1234789012-
prs-AF   1.234.567.890,1234789012-
ps-AF    1،234،567،890,1234789012-
as-IN    -1,23,45,67,890.1234789012
lo-LA    (1234567,890.1234789012)
qps-PLOC --12,,3456,,7890..1234789012

If you're working with a multithreaded system, such as ASP.Net, you can change the thread's CurrentCulture property. Changing the thread's culture will allow all of the associated ToString and String.Format calls to use that culture.

Update

Since you're wanting to display all of the precision you're going to have to do a bit of work. Using NumberFormat.NumberDecimalDigits will work, except that if the value has less precision, the number will output with trailing zeros. If you need to make sure you display every digit without any extras, you will need to calculate the precision beforehand and set that before you convert it to a string. The StackOverflow question Calculate System.Decimal Precision and Scale may be able to help you determine the precision of the decimal.

于 2012-07-10T14:40:06.063 回答