字符串转译

NSString *url = @"https://www.baidu.com/s?ie=UTF-8&wd=%E6%88%91%E7%9A%84%E5%89%8D%E5%8D%8A%E7%94%9F";

    CFStringRef encodedCFString = CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,

                                                                          (__bridgeCFStringRef) url,

                                                                          nil,

                                                                          CFSTR("?!@#$^&%*+,:;='\"`<>()[]{}/\\| "),

                                                                          kCFStringEncodingUTF8);

    NSString*encodedString1 = [[NSStringalloc]initWithString:(__bridge_transferNSString*) encodedCFString];

    NSString *charactersToEscape = @"?!@#$^&%*+,:;='\"`<>()[]{}/\\| ";

    NSCharacterSet *allowedCharacters = [[NSCharacterSet characterSetWithCharactersInString:charactersToEscape] invertedSet];

    NSString *encodedUrl = [url stringByAddingPercentEncodingWithAllowedCharacters:allowedCharacters];

    NSLog(@"\n%@\n%@\n%@",encodedUrl,encodedString1);

参考资料：http://blog.csdn.net/lidongxuedecsdn/article/details/50497998