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ios - 使用socket传输字符串,系统会自动将 NSString 转为 NSData 传输.

本意是想传输一系列16进制的字符串.而NSData类型会将 NSString 转为16进制的 ASCII 码.有什么方法可以直接传输16进制的数据么.

PHPzPHPz2887 days ago338

reply all(1)I'll reply

  • 高洛峰

    高洛峰2017-04-17 17:32:49

    //Write an NSData type data
    +(NSMutableData)HexStringToData:(NSString)str{

    
    NSString *command = str;
    command = [command stringByReplacingOccurrencesOfString:@" " withString:@""];
    NSMutableData *commandToSend= [[NSMutableData alloc] init];
    unsigned char whole_byte;
    char byte_chars[3] = {'rrreee','rrreee','rrreee'};
    int i;
    for (i=0; i < [command length]/2; i++) {
        byte_chars[0] = [command characterAtIndex:i*2];
        byte_chars[1] = [command characterAtIndex:i*2+1];
        whole_byte = strtol(byte_chars, NULL, 16);
        [commandToSend appendBytes:&whole_byte length:1];
    }
    return commandToSend;

    }
    To add: the Str passed in here is already a hexadecimal number.
    For example, when sending a string: JLBT, it should first be converted into hexadecimal: NSString * Str = @"4a4c4254";
    Then the data you send will be hexadecimal data

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