How can I connect QtcpSockets to about 100 servers without a UI hang?
When I create 100 QTcpSockets to connect to each server and call the connectToHost() function, the QDialog stuck. Is there a way to run the connectToHost() part as a background job?
As a result, all connections are made, but while trying to connect (call connectToHost() the UI is in 'No Response' state.
// onConnectToICPMC is the slot function connected to the dialog button pressed signal
void WidgetUploadFile::onConnectToICPMC()
{
// m_tcpClients is a QVector containing a custm QObject Class that manages QTcpSocket
for(int i = 0; i < m_tcpClients.size(); ++i)
{
if(m_tcpClients.at(i)->state() != QAbstractSocket::ConnectedState)
{
m_tcpClients.at(i)->connectToServer(); // Call the connectToHost() function of QTcpSocket.
}
emit sendConnProgBarUpdate(i+1);
emit sendCurrentSockLog(m_tcpClients.at(i)->ipAddress(), m_tcpClients.at(i)->state());
}
}
A dialog that hangs while each QTcpSocket connects to the server.:
Time-consuming tasks should not be run on the main thread. In that case there are 2 strategies:
In this case I think the second option is the best using QTimeLine
.
*.h
private:
void handleFrameChanged(int i);
QTimeLine timeLine;
*.cpp
{
// constructor
timeLine.setRange(0, m_tcpClients.size()-1);
connect(&timeLine, &QTimeLine::frameChanged, this, &WidgetUploadFile::handleFrameChanged);
}
void WidgetUploadFile::onConnectToICPMC()
{
timeLine.start();
}
void WidgetUploadFile::handleFrameChanged(int i){
auto client = m_tcpClients.at(i);
if(client->state() != QAbstractSocket::ConnectedState){
client->connectToServer();
}
emit sendConnProgBarUpdate(i + 1);
emit sendConnProgBarUpdate(client->ipAddress(), client->state());
}