中文和特殊字元 蘋果自帶的方法是解不了的—–需要自己去控制，以下是程式碼

    - (NSString *)encodeToPercentEscapeString: (NSString *) input  
    {  
        // Encode all the reserved characters, per RFC 3986  
        // (<http://www.ietf.org/rfc/rfc3986.txt>)  
        NSString *outputStr = (NSString *)   
        CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,  
                                                (CFStringRef)input,  
                                                NULL
 
,  
                                                (CFStringRef)@"!*'();:@&=+$,/?%#[]",  
                                                kCFStringEncodingUTF8);  
        return outputStr;  
    }  

    - (NSString *)decodeFromPercentEscapeString: (NSString *) input  
    {  
        NSMutableString
 
 *outputStr = [NSMutableString stringWithString:input];  
        [outputStr replaceOccurrencesOfString:@"+"  
                                   withString:@" "  
                                      options:NSLiteralSearch  
                                        range:NSMakeRange(0, [outputStr length])];  

        return
 
 [outputStr stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];  
    }