Qt QByteArray或者Char转十六进制 QString

1、QByteArray转十六进制

 QByteArray buff = sp->readAll();     
 qDebug() << buff.toHex() << " len: " << nLen;

2、Char转十六进制

  QByteArray buff;
    buff.resize( 2);

    buff[0] = 0x55;
    buff[1] = 0x45;

    QString strHex = QString::number( buff.at(0), 16);

3、QString转QByteArray

QByteArray text = QByteArray::fromHex(strHex.toLatin1());