QString与QByteArray互转、字符串转十六进制

1、QByteArray转QString，主要用buf.toHex()即可：

    static QString ByteArrayToHexStr(QByteArray buf)
    {
        QString retStr;
        retStr.append(buf.toHex());
        return retStr;
    }

2、QString转QByteArray

    //第一种：data.toLatin1()
    static QByteArray TwoHexStrToByteArray(QString data)
    {
        QByteArray buf;
        buf = data.toLatin1();
        return buf;
    }

    //第二种：data.toUtf8()也可以
    static QByteArray TwoHexStrToByteArray(QString data)
    {
        QByteArray bytes = data.toUtf8(); // QString转QByteArray方法1
        return bytes;
    }

    //第三种：直接截取在转也可以
    static QByteArray TwoHexStrToByteArray(QString data)
    {
        QByteArray buf;
        for(int i = 0; i < data.length(); i += 2)
        {
            bool ok;            
            char chr = (data.mid(i, 2).toInt(&ok, 16)) & 0xFF;
            buf.append(chr);
        }
        return buf;
    }

3、十六进制字符串转十六进制编码

char ConvertHexChar(char ch)
{
    if((ch >= '0') && (ch <= '9'))
        return ch-0x30;
    else if((ch >= 'A') && (ch <= 'F'))
        return ch-'A'+10;
    else if((ch >= 'a') && (ch <= 'f'))
        return ch-'a'+10;
    else return (-1);
}
 
 
void StringToHex(QString str, QByteArray &senddata)
{
    int hexdata,lowhexdata;
    int hexdatalen = 0;
    int len = str.length();
    senddata.resize(len/2);
    char lstr,hstr;
    for(int i=0; i= len)
            break;
        lstr = str[i].toAscii();
        hexdata = ConvertHexChar(hstr);
        lowhexdata = ConvertHexChar(lstr);
        if((hexdata == 16) || (lowhexdata == 16))
            break;
        else
            hexdata = hexdata*16+lowhexdata;
        i++;
        senddata[hexdatalen] = (char)hexdata;
        hexdatalen++;
    }
    senddata.resize(hexdatalen);
}