c# – 双精度数据类型,小数位后计数小数

下面的方法应该回答“小数精度,尾随数量的数量,这个(双重)值有什么？”.当值看起来像5900.43,5900.043等时,我做对了.当方法收到5900.00时,它返回0,这是错误的(在我的需要).

/// <summary>
   /// Return count of decimals after decimal-place 
   /// </summary>
   private int getDecimalCount(double val)
   {
        int count = 0;
        ...
        return count;
   }

参数’val’是(此方法的正常值的样本)

5900.00返回2
5900.09返回2
5900.000返回3
5900.001返回3
1.0返回1
0.0000005返回7
1.0000000返回7
5900822返回0

我的问题是计算.0 .00 .000等等

题：
我该如何解决这个问题？如果这种方法不可能与双打,怎么回事？

[EDITED]
– 进行小的文本更改以提出更明确的问题,
– 由于’小数位’的错误使用含义导致的语言更正

解决方法

编辑：更新以简化处理不同文化.

与@Miguel类似,这是我将如何处理它：

public static int getDecimalCount(double dVal,string sVal,string culture)
{
    CultureInfo info = CultureInfo.GetCultureInfo(culture);

    //Get the double value of the string representation,keeping culture in mind
    double test = Convert.Todouble(sVal,info);

    //Get the decimal separator the specified culture
    char[] sep = info.NumberFormat.NumberDecimalSeparator.tochararray();

    //Check to see if the culture-adjusted string is equal to the double
    if (dVal != test)
    {
        //The string conversion isn't correct,so throw an exception
        throw new System.ArgumentException("dVal doesn't equal sVal for the specified culture");
    }

    //Split the string on the separator 
    string[] segments = sVal.Split(sep);

    switch (segments.Length)
    {
        //Only one segment,so there was not fractional value - return 0
        case 1:
            return 0;
        //Two segments,so return the length of the second segment
        case 2:
            return segments[1].Length;

        //More than two segments means it's invalid,so throw an exception
        default:
            throw new Exception("Something bad happened!");
    }
}

美国英语的快捷方法：

public static int getDecimalCount(double dVal,string sVal)
{
    return getDecimalCount(dVal,sVal,"en-US");
}

测试：

static void Main(string[] args)
{
    int i = 0;

    double d = 5900.00; 
    string s = "5900.00";
    Console.WriteLine("Testing with dVal = {0} and sVal = {1}.",d,s);
    i = getDecimalCount(d,s);
    Console.WriteLine("Expected output: 2. Actual output: {0}",i);
    Console.WriteLine();

    d = 5900.09;
    s = "5900.09";
    Console.WriteLine("Testing with dVal = {0} and sVal = {1}.",i);
    Console.WriteLine();

    d = 5900.000;
    s = "5900.000";
    Console.WriteLine("Testing with dVal = {0} and sVal = {1}.",s);
    Console.WriteLine("Expected output: 3. Actual output: {0}",i);
    Console.WriteLine();

    d = 5900.001;
    s = "5900.001";
    Console.WriteLine("Testing with dVal = {0} and sVal = {1}.",i);
    Console.WriteLine();

    d = 1.0; 
    s = "1.0";
    Console.WriteLine("Testing with dVal = {0} and sVal = {1}.",s);
    Console.WriteLine("Expected output: 1. Actual output: {0}",i);
    Console.WriteLine();

    d = 0.0000005; 
    s = "0.0000005";
    Console.WriteLine("Testing with dVal = {0} and sVal = {1}.",s);
    Console.WriteLine("Expected output: 7. Actual output: {0}",i);
    Console.WriteLine();

    d = 1.0000000; 
    s = "1.0000000";
    Console.WriteLine("Testing with dVal = {0} and sVal = {1}.",i);
    Console.WriteLine();

    d = 5900822; 
    s = "5900822";
    Console.WriteLine("Testing with dVal = {0} and sVal = {1}.",s);
    Console.WriteLine("Expected output: 0. Actual output: {0}",i);

    Console.ReadLine();
}

最后,测试的输出：

Testing with dVal = 5900 and sVal = 5900.00.
Expected output: 2. Actual output: 2

Testing with dVal = 5900.09 and sVal = 5900.09.
Expected output: 2. Actual output: 2

Testing with dVal = 5900 and sVal = 5900.000.
Expected output: 3. Actual output: 3

Testing with dVal = 5900.001 and sVal = 5900.001.
Expected output: 3. Actual output: 3

Testing with dVal = 1 and sVal = 1.0.
Expected output: 1. Actual output: 1

Testing with dVal = 5E-07 and sVal = 0.0000005.
Expected output: 7. Actual output: 7

Testing with dVal = 1 and sVal = 1.0000000.
Expected output: 7. Actual output: 7

Testing with dVal = 5900822 and sVal = 5900822.
Expected output: 0. Actual output: 0

如果您对此有疑问或者没有意义,请告诉我.