C＃Decimal.Parse问题用逗号 [英] C# Decimal.Parse issue with commas

问题描述

下面是我的问题（为EN-US）：

Here's my problem (for en-US):

Decimal.Parse（1,2,3,4）返回1​​234，而不是抛出一个InvalidFormatException。

Decimal.Parse("1,2,3,4") returns 1234, instead of throwing an InvalidFormatException.

大多数Windows应用程序（Excel的EN-US）不落千位分隔符，没有考虑该值的十进制数。同样的问题发生其他语言（虽然具有不同的字符）。

Most Windows applications (Excel en-US) do not drop the thousand separators and do not consider that value a decimal number. The same issue happens for other languages (although with different characters).

有没有解决这个问题的任何其他十进制解析库在那里？

Are there any other decimal parsing libraries out there that solve this issue?

谢谢！

推荐答案

我最后不得不写code手动验证货币。就个人而言，对于自诩具有所有的东西全球化内置了一个框架，这是惊人的.NET不有什么处理这个问题。

I ended up having to write the code to verify the currency manually. Personally, for a framework that prides itself for having all the globalization stuff built in, it's amazing .NET doesn't have anything to handle this.

我的解决办法如下。它的工作原理在框架所有的地区。它不支持负数，猎户座下面指出的那样，虽然。你们有什么想的？

My solution is below. It works for all the locales in the framework. It doesn't support Negative numbers, as Orion pointed out below, though. What do you guys think?

    public static bool TryParseCurrency(string value, out decimal result)
    {
        result = 0;
        const int maxCount = 100;
        if (String.IsNullOrEmpty(value))
            return false;

        const string decimalNumberPattern = @"^\-?[0-9]{{1,{4}}}(\{0}[0-9]{{{2}}})*(\{0}[0-9]{{{3}}})*(\{1}[0-9]+)*$";

        NumberFormatInfo format = CultureInfo.CurrentCulture.NumberFormat;

        int secondaryGroupSize = format.CurrencyGroupSizes.Length > 1
                ? format.CurrencyGroupSizes[1]
                : format.CurrencyGroupSizes[0];

        var r = new Regex(String.Format(decimalNumberPattern
                                       , format.CurrencyGroupSeparator==" " ? "s" : format.CurrencyGroupSeparator
                                       , format.CurrencyDecimalSeparator
                                       , secondaryGroupSize
                                       , format.CurrencyGroupSizes[0]
                                       , maxCount), RegexOptions.Compiled | RegexOptions.CultureInvariant);
        return !r.IsMatch(value.Trim()) ? false : Decimal.TryParse(value, NumberStyles.Any, CultureInfo.CurrentCulture, out result);
    }

而这里的一个测试，以显示它的工作（NUnit的）：

And here's one test to show it working (nUnit):

    [Test]
    public void TestCurrencyStrictParsingInAllLocales()
    {
        var originalCulture = CultureInfo.CurrentCulture;
        var cultures = CultureInfo.GetCultures(CultureTypes.SpecificCultures);
        const decimal originalNumber = 12345678.98m;
        foreach(var culture in cultures)
        {
            var stringValue = originalNumber.ToCurrencyWithoutSymbolFormat();
            decimal resultNumber = 0;
            Assert.IsTrue(DecimalUtils.TryParseCurrency(stringValue, out resultNumber));
            Assert.AreEqual(originalNumber, resultNumber);
        }
        System.Threading.Thread.CurrentThread.CurrentCulture = originalCulture;

    }

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