Qt c++ application results QNetworkReply::UnknownNetworkError error after network restart

qt_newbee

Hi there,

I am using Qt5.15 version for my application. My application is a basic server client application and with some custom features like monitoring wifi connection, in Linux. I am initializing a QNetworkAccessManager object to send and receive the data from my AWS server. The application runs without any issue until there is a network connectivity problem. If there is a network connectivity issue (wifi is not connected), I am restarting the network services using Linux commands. After the network is restarted, for the very first call to my AWS server, the QT debug prints are:
- Network error QNetworkReply::UnknownNetworkError received
(unknown:0) - QIODevice::read (QDisabledNetworkReply): device not open

I tried to print the error code, and it was 99. I am not able to find the root cause and unable to make the API call pass. If I restart the application works. What should I do in the QT code to fix the application without restarting the same.

Looking forward to possible solutions.
Thanks.

SGaist

Hi and welcome to devnet,

What if you recreate your QNAM object ?

qt_newbee

@SGaist Thanks for your response. I cannot create a new object for the QNAM. Because, the same object is being associated to different function. I would need to use the same object for the application. I couldn't get a proper example for re-initializing the QNAM object with the same object name. Could you please help me on that.

Thanks in Advance!

SGaist

delete _qnam;
_qnam = new QNetworkAccessManager(this);
// do all the connections.

qt_newbee

@SGaist Thanks for the code snippet example. I will try the same and update whether it works.

Best Regards.

qt_newbee

@SGaist You saved my time. Thanks for the input and my application worked after I have recreated the QNAM object and connected the necessary signals and slots into my current context. Thanks for your support.