NSString 转为gbk

NSString *parameterUrlStr = [NSString stringWithFormat:@"中文的字体"];

NSStringEncoding gbkEncoding = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);

NSString *url = [parameterUrlStr stringByAddingPercentEscapesUsingEncoding:gbkEncoding];