QDataStream in(&tcp);
in.setVersion(QDataStream::Qt_DefaultCompiledVersion);
if (!blockSize)
    if(tcp.bytesAvailable() < sizeof(quint16))
        return;
in >> blockSize;
if (tcp.bytesAvailable() < blockSize)
    return;
QStringList str;
in >> str;
ui->listWidget->addItems(str);
blockSize = 0;