URL编码 encode

#define CFSTR(cStr)  ((CFStringRef) __builtin___CFStringMakeConstantString ("" cStr
""))

+ (NSString *)encodeURL:(NSString *)string endcode:(NSStringEncoding)stringEncoding

{

NSString *newString = NSMakeCollectable([(NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)string, NULL,
CFSTR(":/?#[]@!$ &'()*+,;=\"<>%{}|\\^~`"), CFStringConvertNSStringEncodingToEncoding(stringEncoding)) autorelease]);

if (newString) {

return newString;

}

return @"";

}