您可以尝试像

var decomposed = "áéö".Normalise(NormalizationForm.FormD);
var filtered = decomposed.Where(c => char.GetUnicodeCategory(c) != UnicodeCategory.NonSpacingMark);
var newString = new String(filtered.ToArray());

这口音分解从文本，过滤它们，并创建一个新的字符串。结合变音符号都在非间距标记的Unicode 的类别。

This decomposes accents from the text, filters them and creates a new string. Combining diacritics are in the Non spacing mark unicode category.