Question

What is wrong with the code:

if i use system proxy the error displayed is “connection refused”
and if i use manual proxy (proxy address being same) error displayed is “Host not found”

The proxy server is squid with proxy-address:172.16.28.11 and port:3128

Besides, it also doesn’t work for localhost proxy like the one created using “tor” or dynamic port forwarding!

if(settDialog.ui->no_proxy->isChecked())
{
    QNetworkProxyFactory::setUseSystemConfiguration (false);
    QNetworkProxy::setApplicationProxy(QNetworkProxy::NoProxy);
}
else if(settDialog.ui->use_s_proxy->isChecked())
{
    QNetworkProxyFactory::setUseSystemConfiguration (true);
}
else if(settDialog.ui->man_proxy->isChecked())
{
    QNetworkProxyFactory::setUseSystemConfiguration (false);
    proxy.setHostName(settDialog.ui->proxy_addr->text());
    proxy.setPort(settDialog.ui->port_num->value());
    if(settDialog.ui->proxyType->currentIndex()==0)
        proxy.setType(QNetworkProxy::HttpProxy);
    else if(settDialog.ui->proxyType->currentIndex()==1)
        proxy.setType(QNetworkProxy::Socks5Proxy);
    else if(settDialog.ui->proxyType->currentIndex()==2)
        proxy.setType(QNetworkProxy::FtpCachingProxy);
    proxy.setHostName(settDialog.ui->username->text());
    proxy.setPassword(settDialog.ui->pwd->text());
    QNetworkProxy::setApplicationProxy(proxy);
}

Answer 1

I may be over-simplifying things, but this looks like this is a simple incorrect API call.

proxy.setHostName is where you define the host name of the proxy server, you set the user name through the proxy.setUser API, i.e:

proxy.setUser(settDialog.ui->username->text());