QString str = "01 a5 1e 02";

 QByteArray tmpBy;

 StringToHex(str, tmpBy);

 void MainWindow::StringToHex(QString str, QByteArray &senddata)

 {

     int hexdata,lowhexdata;

     int hexdatalen = ;

     int len = str.length();

     senddata.resize(len/);

     char lstr,hstr;

     for(int i=; i<len; )

     {

         //char lstr,

         hstr=str[i].toLatin1();

         if(hstr == ' ')

         {

             i++;

             continue;

         }

         i++;

         if(i >= len)

             break;

         lstr = str[i].toLatin1();

         hexdata = ConvertHexChar(hstr);

         lowhexdata = ConvertHexChar(lstr);

         if((hexdata == ) || (lowhexdata == ))

             break;

         else

             hexdata = hexdata*+lowhexdata;

         i++;

         senddata[hexdatalen] = (char)hexdata;

         hexdatalen++;

     }

     senddata.resize(hexdatalen);

 }

 char MainWindow::ConvertHexChar(char ch)

 {

     if((ch >= '') && (ch <= ''))

         return ch-0x30;

     else if((ch >= 'A') && (ch <= 'F'))

         return ch-'A'+;

     else if((ch >= 'a') && (ch <= 'f'))

         return ch-'a'+;

     else return ch-ch;//不在0-f范围内的会发送成0

 }

     QDataStream out(&requestData,QIODevice::ReadWrite);    //将字节数组读入

     QString strReceive;

     int index = ;

     while(!out.atEnd())

     {

         qint8 outChar = ;

         out>>outChar;   //每字节填充一次，直到结束

         //十六进制的转换

         QString str = QString("%1").arg(outChar & 0xFF,,,QLatin1Char(''));

         strReceive.append(str);

     }