IOS的URL中文以及符号转码

- (NSString *)encodeToPercentEscapeString: (NSString *) input
{
    NSString *outputStr = (NSString *)
    CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                                            (CFStringRef)input,
                                            NULL,
                                            (CFStringRef)@"!*‘();:@&=+$,/?%#[]",
                                            kCFStringEncodingUTF8);
    return outputStr;
}