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,)&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 = ;
         out >> outChar;   //每次一个字节的填充到 outchar
         QString str = QString("%1").arg(outChar&0xFF,,,QLatin1Char('')).toUpper() + QString(" ");   //2 字符宽度
         buf += str;
     }
     return buf;
 }

 int main(int argc, char *argv[])
 {
     QCoreApplication a(argc, argv);
     char cmd[] = {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();
 }