您的字符串不仅包含空格，而且还包含换行符.

Your string contains not only whitespace but also new line characters.

将stringByTrimmingCharactersInSet与whitespaceAndNewlineCharacterSet一起使用.

let string = "\r\n\t- Someone will come here?\n- I don't know for sure...\r\n\r\n"
let trimmedString = string.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())

在Swift 3中，清理得更多:

In Swift 3 it's more cleaned up:

let trimmedString = string.trimmingCharacters(in: .whitespacesAndNewlines)