iPhone开发--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.

//NSString+URLEncoding.h
#import 
 
@interface NSString (URLEncodingAdditions)
- (NSString *)URLEncodedString;
- (NSString *)URLDecodedString;
@end

//NSString+URLEncoding.m
#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

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];

转载自：http://www.voland.com.cn/urlencoding_for_objective-c