运算符“！” 不能应用于“方法组”类型的操作数

Question

Probably a duplicate but of the related questions, I've yet to find a solution that works. Trying to count the number of digits up to aa number of character in a string.

Getting the error: '!' cannot be applied to operand of type 'method group'

line.TakeWhile(!Char.IsLetterOrDigit).Count())

Answer 1

您需要在此处使用lambda表达式而不是方法组语法：

line.TakeWhile(x => !Char.IsLetterOrDigit(x)).Count())

Answer 2

the problem is exactly what the error tells you: you cannot use ! on an function (the Char.IsLetterOrDigit ) - one simple solution is expanding it into a lambda:

line.TakeWhile(c => !Char.IsLetterOrDigit(c)).Count())