Qt QByteArray或者Char轉十六進制 QString

1、QByteArray轉十六進制

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

2、Char轉十六進制

  QByteArray buff;
    buff.resize( 2);

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

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

3、QString轉QByteArray

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