NSString *strUrl = [urlString stringByReplacingOccurrencesOfString:@" " withString:@""]; 去掉空格
NSString *strUrl = [urlString stringByReplacingOccurrencesOfString:@" " withString:@"/"];替换字符
iOS 字符串的操作，去掉某一个字符或者替换成其他字符
原文：http://www.cnblogs.com/cui-cui/p/6379227.html
