NSString+URLEncoding.h --使用Obj-C对数据等进行URLEncoding编码

在Objective-c进行网络编程时,经常需要把数据转换成URLEncoding编码,如对+号编码后,变成%2b.这里我们给出一种实现.

#import
@interface NSString (URLEncodingAdditions)
- (NSString *)URLEncodedString;
- (NSString *)URLDecodedString;
@end</span>

#import "NSString+URLEncoding.h"
@implementation NSString (OAURLEncodingAdditions)
- (NSString *)URLEncodedString
{
    NSString *result = (NSString *)
       CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                                                  (CFStringRef)self,
                                                  NULL,
                                                  CFSTR("!*'();:@&=+$,/?%#[] "),
                                                  kCFStringEncodingUTF8);
    [result autorelease];
return result;
}
- (NSString*)URLDecodedString
{
    NSString *result = (NSString *)
       CFURLCreateStringByReplacingPercentEscapesUsingEncoding(kCFAllocatorDefault,
                        (CFStringRef)self,
                        CFSTR(""),
                        kCFStringEncodingUTF8);
    [result autorelease];
return result;
}
@end</span>

因为是扩展了NSString,使用的时候就比较简单了,首先在使用本类的文件中引入NSString+URLEncoding.h头文件,然后直接用NSString中的URLEncodedString与URLDecodedString方法,如:
NSString *urlToken = [token URLEncodedString];