Question

可能重复：
how to recognize similar words with difference in spelling

我在尝试比较这3个字符串时返回true： 'voest'，'vost'和'vöst'（德国文化），因为它是同一个词。（事实上，只有oe和ö是相同的，但是例如对于DB校对CI它是正确的，因为'vost'是错误的'voest'）

无论我为该方法提供什么参数，

string.Compare（..）/ string.Equals（..）都返回false。

如何使string.Compare（）/ Equals（..）返回true？

Answer 1

您可以创建一个忽略变音符号的自定义比较器：

class IgnoreUmlautComparer : IEqualityComparer<string>
{
    Dictionary<char, char> umlautReplacer = new Dictionary<char, char>()
    {
        {'ä','a'}, {'Ä','A'},
        {'ö','o'}, {'Ö','O'},
        {'ü','u'}, {'Ü','U'},
    };
    Dictionary<string, string> pseudoUmlautReplacer = new Dictionary<string, string>()
    {
        {"ae","a"}, {"Ae","A"},
        {"oe","o"}, {"Oe","O"},
        {"ue","u"}, {"Ue","U"},
    };

    private IEnumerable<char> ignoreUmlaut(string s)
    {
        char value;
        string replaced = new string(s.Select(c => umlautReplacer.TryGetValue(c, out value) ? value : c).ToArray());
        foreach (var kv in pseudoUmlautReplacer)
            replaced = replaced.Replace(kv.Key, kv.Value);
        return replaced;
    }

    public bool Equals(string x, string y)
    {
        var xChars = ignoreUmlaut(x);
        var yChars = ignoreUmlaut(y);
        return xChars.SequenceEqual(yChars);
    }

    public int GetHashCode(string obj)
    {
        return ignoreUmlaut(obj).GetHashCode();
    }
}

现在，您可以将此比较器与Distinct之类的Enumerable方法一起使用：

string[] allStrings = new[]{"voest","vost","vöst"};
bool allEqual = allStrings.Distinct(new IgnoreUmlautComparer()).Count() == 1;
// --> true

Answer 2

您可以在比较中尝试IgnoreNonSpace选项。它不会解决voest - vost，但会对vost-vöst有帮助。

int a = new CultureInfo("de-DE").CompareInfo.Compare("vost", "vöst", CompareOptions.IgnoreNonSpace);
// a = 0; strings are equal.

C＃字符串比较'ö''oe''o'

2 个答案: