QByteArray和十六进制的QString（char*）相互转换

#include <QCoreApplication>
#include <QDebug>
#include <QDataStream>

QByteArray HexStringToByteArray(QString HexString)
{
    bool ok;
    QByteArray ret;
    HexString = HexString.trimmed();
    HexString = HexString.simplified();
    QStringList sl = HexString.split(" ");

    foreach (QString s, sl) {
        if(!s.isEmpty()) {
            char c = s.toInt(&ok,16)&0xFF;
            if(ok){
                ret.append(c);
            }else{
                qDebug()<<"非法的16进制字符："<<s;
            }
        }
    }
    return ret;
}

QString ByteArrayToHexString(QByteArray &ba)
{
    QDataStream out(&ba,QIODevice::ReadWrite);   //将str的数据 读到out里面去
    QString buf;
    while(!out.atEnd())
    {
        qint8 outChar = 0;
        out >> outChar;   //每次一个字节的填充到 outchar
        QString str = QString("%1").arg(outChar&0xFF,2,16,QLatin1Char('0')).toUpper() + QString(" ");   //2 字符宽度
        buf += str;
    }
    return buf;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    char cmd[7] = {0x40, 0x00, 0x00, 0x01, 0x00, 0x41, 0x0A};
    char* cmdString = "40 00 00 01 00 41 0a";
    QByteArray cmdBA = HexStringToByteArray(cmdString);
    qDebug()<<ByteArrayToHexString(cmdBA);

    return a.exec();
}