Char.IsSurrogate(c)

Char.IsSymbol(c)

Char.IsWhiteSpace(c)

Char.IsUpper(c)

'Char转换

Char.ToLower(c)

Char.ToUpper(c)

'字符串操作

cc = s.ToCharArray()

ss = s.Split(",")

s = s.Substring(5, 3)

s = s.Trim()