碰巧用到，记录一下：
using System.Globalization;
using System.Threading;
CultureInfo cultureInfo = Thread.CurrentThread.CurrentCulture;
TextInfo textInfo = cultureInfo.TextInfo;
Console.WriteLine(textInfo.ToTitleCase(title));
Console.WriteLine(textInfo.ToLower(title));
Console.WriteLine(textInfo.ToUpper(title));
using System.Globalization; using System.Threading; CultureInfo cultureInfo = Thread.CurrentThread.CurrentCulture; TextInfo textInfo = cultureInfo.TextInfo; Console.WriteLine(textInfo.ToTitleCase(title)); Console.WriteLine(textInfo.ToLower(title)); Console.WriteLine(textInfo.ToUpper(title));