//if(myCom->open(QIODevice::ReadWrite)){
// QMessageBox::information(this, codec->toUnicode("打开成功"), tr("Already open serial ") + portName, QMessageBox::Ok);
// //QMessageBox::information(this, tr("打开成功"), tr("Already open serial ") + portName, QMessageBox::Ok);
//}else{
// QMessageBox::critical(this, tr("Open failure"), tr("Can not open serial ") + portName + tr("\n The serial unvaliable"), QMessageBox::Ok);
// return;
//}
上述代码给出了打开串口成功或者失败时候都能给出messagebox的提示,希望对你有用