在Objective-c進行網路程式設計時,經常需要把資料轉換成URLEncoding編碼,如對+號編碼後,變成%2b.這裡我們給出一種實現.

//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
 

轉載自：http://www.voland.com.cn/urlencoding_for_objective-c