iOS, C++开发常见的数据转换

前言: 在项目中, 经常遇到需要各种数据之间转换的, 虽然简单但是却没有必要每个都记住. 所以每次都要去网上查询一番, 很是繁琐.于是决定把自己遇到的都记录在这篇文章里(随时遇到随时更新), 方便以后使用.希望对大家也有所帮助!

Base64编码

/**
* @description: Base64编码
* BCB6 C++
* @param1:  Data:数据
* @param2:  DataLen:数据长度
* @return: AnsiString(字符串)
*/
AnsiString TIDCard::EncodeBase64(const unsigned char* Data,int DataLen)
{
    //编码表
    const char EncodeTable[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    //返回值
    AnsiString strEncode;
    unsigned char Tmp[4]={0};
    int LineLength=0;
    for(int i=0;i<(int)(DataLen / 3);i++)
    {
        Tmp[1] = *Data++;
        Tmp[2] = *Data++;
        Tmp[3] = *Data++;
        strEncode+= EncodeTable[Tmp[1] >> 2];
        strEncode+= EncodeTable[((Tmp[1] << 4) | (Tmp[2] >> 4)) & 0x3F];
        strEncode+= EncodeTable[((Tmp[2] << 2) | (Tmp[3] >> 6)) & 0x3F];
        strEncode+= EncodeTable[Tmp[3] & 0x3F];
        if(LineLength+=4,LineLength==76) {
                //strEncode+="\r\n";
                LineLength=0;
        }
    }
    //对剩余数据进行编码
    int Mod=DataLen % 3;
    if(Mod==1)
    {
        Tmp[1] = *Data++;
        strEncode+= EncodeTable[(Tmp[1] & 0xFC) >> 2];
        strEncode+= EncodeTable[((Tmp[1] & 0x03) << 4)];
        strEncode+= "==";
    }
    else if(Mod==2)
    {
        Tmp[1] = *Data++;
        Tmp[2] = *Data++;
        strEncode+= EncodeTable[(Tmp[1] & 0xFC) >> 2];
        strEncode+= EncodeTable[((Tmp[1] & 0x03) << 4) | ((Tmp[2] & 0xF0) >> 4)];
        strEncode+= EncodeTable[((Tmp[2] & 0x0F) << 2)];
        strEncode+= "=";
    }

    return strEncode;
}

Base64解码

/**
* @description: Base64解码
* BCB6 C++
* @param1:  Data:数据
* @param2:  DataLen:输入数据长度
* @param3:  OutLen:输出数据长度
* @return: AnsiString(字符串)
*/
AnsiString TIDCard::Decode(const char* Data,int DataLen,int& OutLen)
{
    //解码表
    const char DecodeTable[] =
    {
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        62, // '+'
        0, 0, 0,
        63, // '/'
        52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9'
        0, 0, 0, 0, 0, 0, 0,
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
        13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 'A'-'Z'
        0, 0, 0, 0, 0, 0,
        26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
        39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // 'a'-'z'
    };
    //返回值
    AnsiString strDecode;
    int nValue;
    int i= 0;
    while (i < DataLen)
    {
        if (*Data != '\r' && *Data!='\n')
        {
            nValue = DecodeTable[*Data++] << 18;
            nValue += DecodeTable[*Data++] << 12;
            strDecode+=(nValue & 0x00FF0000) >> 16;
            OutLen++;
            if (*Data != '=')
            {
                nValue += DecodeTable[*Data++] << 6;
                strDecode+=(nValue & 0x0000FF00) >> 8;
                OutLen++;
                if (*Data != '=')
                {
                    nValue += DecodeTable[*Data++];
                    strDecode+=nValue & 0x000000FF;
                    OutLen++;
                }
            }
            i += 4;
        }
        else// 回车换行,跳过
        {
            Data++;
            i++;
        }
     }
    return strDecode;
}

byte数组转字符串

/**
* @description: byte数组转字符串
* BCB6 C++
* @param1:  in:输入数据
* @param2:  length:输出数据长度
* @return: AnsiString(字符串)
*/
AnsiString TSamThread::BytetoStr(byte *in, int length)
{
       AnsiString sTraceOut = "";
       for (int i=0;i<length;i++)
       sTraceOut += IntToHex (in[i],2)+"";
       return sTraceOut;
}

转换卡号 0123456789->1032547698 第一二位对换、三四位对换...

/**
* Object-C(iOS开发)
* @param1:  cardNumber:输入的号码
* @return: NSString(字符串)
*/
- (NSString *)dealCardNumber:(NSString *)cardNumber
{
    NSInteger cardLength = cardNumber.length;
    NSString *cardNum = @"";
    for(NSInteger i = 0; i < cardLength; i++) {
        if(i%2 == 0) {
            cardNum = [cardNum stringByAppendingString:[NSString stringWithFormat:@"%c", [cardNumber characterAtIndex:i + 1]]];
        }
        else{
            cardNum = [cardNum stringByAppendingString:[NSString stringWithFormat:@"%c", [cardNumber characterAtIndex:i - 1]]];
        }
    }
    return cardNum;
}

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