URL特殊字符的转义

http://blog.csdn.net/sunyujia/article/details/2205364

http://blog.csdn.net/worldzhy/article/details/41945999

特殊符号 十六进制值

+ 转义符为 %2B

空格 转义符为 + 或 %20

/ 转义符为 %2F

? 转义符为 %3F

% 转义符为 %25

# 转义符为 %23

& 转义符为 %26

= 转义符为 %3D

NSString *str = @"http%3A%2F%2Fmyimg.ifeng.com%2F200%2F22%2F8a941d71c4df48a5%2F1418632228%2F8a941d71c4df48a5_1.jpg"

NSString *strUrl = [str decodeURL];

NSLog(@"%@", strUrl);

打印结果：http://myimg.ifeng.com/200/22/8a941d71c4df48a5/1418632228/8a941d71c4df48a5_1.jpg