URL的编码字符串

Question

我必须从Iphone应用程序将数据发布到php页面,所以我需要正确编码参数,转换特殊字符...

特别是我需要发送iPhone的UDID.

我在网上找到了许多帮助编码String作为参数传递,但我得到一个奇怪的错误.

我正在使用这个功能:

- (NSString *)URLEncodeString:(NSString *)string { 

NSString *result =
   (NSString*)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, 
    (CFStringRef)string, NULL, CFSTR("'\"?=&+<>;:-"), kCFStringEncodingUTF8);

return [result autorelease];}

它似乎是正确的,但当我使用它时,结果不是我所期望的.

这是代码:

UIDevice *device = [UIDevice currentDevice];
NSString *uniqueIdentifier = [device uniqueIdentifier];

NSLog(uniqueIdentifier);
NSLog([self URLEncodeString:uniqueIdentifier]);

这是我点击此代码时生成的日志:

2010-06-23 21:58:51.671 provaNavigation[2343:20b] 00000000-0000-1000-8000-0013775CE6D2
2010-06-23 21:58:51.672 provaNavigation[2343:20b] 0000000010003900009080176010001273086780001283520013775CE6D2

然后再次:

2010-06-23 21:59:25.614 provaNavigation[2343:20b] 00000000-0000-1000-8000-0013775CE6D2
2010-06-23 21:59:25.615 provaNavigation[2343:20b] 000000001000390000908192801000-18000912258750013775CE6D2

然后再次:

2010-06-23 21:59:40.848 provaNavigation[2343:20b] 00000000-0000-1000-8000-0013775CE6D2
2010-06-23 21:59:40.849 provaNavigation[2343:20b] 000000001000390000908866081000-18000912239630013775CE6D2

然后再次...

我每次都会获得不同的值,并且永远不会使用正确的%编号进行更正.

Answer 1

我之前遇到过URL编码问题,所以我最后在NSString上编写了一个类别来正确编码URL:

- (NSString *) URLEncodedString {
  NSMutableString * output = [NSMutableString string];
  const char * source = [self UTF8String];
  int sourceLen = strlen(source);
  for (int i = 0; i < sourceLen; ++i) {
    const unsigned char thisChar = (const unsigned char)source[i];
    if (thisChar == ' '){
      [output appendString:@"+"];
    } else if (thisChar == '.' || thisChar == '-' || thisChar == '_' || thisChar == '~' || 
           (thisChar >= 'a' && thisChar <= 'z') ||
           (thisChar >= 'A' && thisChar <= 'Z') ||
           (thisChar >= '0' && thisChar <= '9')) {
      [output appendFormat:@"%c", thisChar];
    } else {
      [output appendFormat:@"%%%02X", thisChar];
    }
  }
  return output;
}

- (NSString *) URLDecodedString {
  NSString * spacedDecoded = [self stringByReplacingOccurrencesOfString:@"+" withString:@" "];
  return [spacedDecoded stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
}

有几个关于此的说明:

1. 这会将空格编码为"+"
2. 这将编码除az(大写和小写),数字,句点,连字符,下划线和波形符之外的所有内容

3. 这将正确编码unicode字符为多个八位字节.例如,我可以这样做:

   NSString * enc = [@"http://example.com/?data=÷¡¿" URLEncodedString];
   NSLog(@"%@", enc);
   NSLog(@"%@", [enc URLDecodedString]);

   哪个会正确记录:

   Testing.m:65 main() http%3A%2F%2Fexample.com%2F%3Fdata%3D%C3%B7%C2%A1%C2%BF
   Testing.m:66 main() http://example.com/?data=÷¡¿

编辑 我将其复制并粘贴到一个空项目中,如下所示:

NSString * string = @"00000000-0000-1000-8000-0013775CE6D2";
NSString *result = (NSString*)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)string, NULL, CFSTR("'\"?=&+<>;:-"), kCFStringEncodingUTF8);
NSLog(@"encode? %@", result);
result = [result stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(@"decode? %@", result);
NSLog(@"equal? %d", [string isEqual:result]);

并记录:

Testing[62541:a0f] encode? 00000000%2D0000%2D1000%2D8000%2D0013775CE6D2
Testing[62541:a0f] decode? 00000000-0000-1000-8000-0013775CE6D2
Testing[62541:a0f] equal? 1

您的代码无法正常工作的原因是因为您将字符串记录为格式字符串,这意味着它正在查看这些%2内容并尝试将其替换为其他内容.注意:

NSString * string = @"00000000-0000-1000-8000-0013775CE6D2";
NSString *result = (NSString*)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)string, NULL, CFSTR("'\"?=&+<>;:-"), kCFStringEncodingUTF8);
NSLog(@"%@", result);
NSLog(result);

日志:

Testing[62585:a0f] 00000000%2D0000%2D1000%2D8000%2D0013775CE6D2
Testing[62585:a0f] 00000000879923200001897296640100041968968000 00013775CE6D2

所以字符串被正确编码,但你只是错误地记录它.