//编码NSString *uniStr = [NSString stringWithUTF8String:[_barrageText.text UTF8String]];

    NSData *uniData = [uniStr dataUsingEncoding:NSNonLossyASCIIStringEncoding];

    NSString *goodStr = [[NSString alloc] initWithData:uniData encoding:NSUTF8StringEncoding] ;

    NSLog(@"---编码--->[%@]",goodStr);

    //解码constchar*jsonString = [goodStr UTF8String];// goodStr 服务器返回的 jsonNSData *jsonData = [NSData dataWithBytes:jsonString length:strlen(jsonString)];

    NSString *goodMsg1 = [[NSString alloc] initWithData:jsonData encoding:NSNonLossyASCIIStringEncoding];

    NSLog(@"---解码--->[%@]",goodMsg1);

    2016-04-1510:16:17.858DFRomwe[650:153981] ---编码--->[hello\ud83d\ude18\ud83d\ude18world\u4e16\u754chaha\ud83d\ude17]

    2016-04-1510:16:17.859DFRomwe[650:153981] ---解码--->[hello😘😘world世界haha😗]