NSString * string=[countString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];//去除首位空格
NSString * string = [countString stringByReplacingOccurrencesOfString:@" "withString:@""];//去除中间空格
NSString * string =[countString stringByReplacingOccurrencesOfString:@"\n"withString:@""];//去除换行符