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.

[cpp] <span style="font-family:SimSun;font-size:13px;color:#330033;">//NSString+URLEncoding.h  
#import   
  
@interface NSString (URLEncodingAdditions) 
- (NSString *)URLEncodedString; 
- (NSString *)URLDecodedString; 
@end</span> 
<span style="font-family:SimSun;font-size:13px;color:#330033;">//NSString+URLEncoding.h
#import
 
@interface NSString (URLEncodingAdditions)
- (NSString *)URLEncodedString;
- (NSString *)URLDecodedString;
@end</span>
[cpp] <span style="font-family:SimSun;font-size:13px;color:#330033;">//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</span> 
<span style="font-family:SimSun;font-size:13px;color:#330033;">//NSString+URLEncoding.m
#import "NSString+URLEncoding.h"
@implementation NSString (OAURLEncodingAdditions)
 
- (NSString *)URLEncodedString
{
    NSString *result = (NSString *)
       CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,