The connection was refused by the peer (or timed out).
QAbstractSocket::RemoteHostClosedError
1
The remote host closed the connection. Note that the client socket (i.e., this socket) will be closed after the remote close notification has been sent.
QAbstractSocket::HostNotFoundError
2
The host address was not found.
QAbstractSocket::SocketAccessError
3
The socket operation failed because the application lacked the required privileges.
QAbstractSocket::SocketResourceError
4
The local system ran out of resources (e.g., too many sockets).
QAbstractSocket::SocketTimeoutError
5
The socket operation timed out.
QAbstractSocket::DatagramTooLargeError
6
The datagram was larger than the operating system's limit (which can be as low as 8192 bytes).
QAbstractSocket::NetworkError
7
An error occurred with the network (e.g., the network cable was accidentally plugged out).
QAbstractSocket::AddressInUseError
8
The address specified to QUdpSocket::bind() is already in use and was set to be exclusive.
QAbstractSocket::SocketAddressNotAvailableError
9
The address specified to QUdpSocket::bind() does not belong to the host.
QAbstractSocket::UnsupportedSocketOperationError
10
The requested socket operation is not supported by the local operating system (e.g., lack of IPv6 support).
QAbstractSocket::ProxyAuthenticationRequiredError
12
The socket is using a proxy, and the proxy requires authentication.
QAbstractSocket::SslHandshakeFailedError
13
The SSL/TLS handshake failed, so the connection was closed (only used in QSslSocket)
QAbstractSocket::UnfinishedSocketOperationError
11
Used by QAbstractSocketEngine only, The last operation attempted has not finished yet (still in progress in the background).
QAbstractSocket::ProxyConnectionRefusedError
14
Could not contact the proxy server because the connection to that server was denied
QAbstractSocket::ProxyConnectionClosedError
15
The connection to the proxy server was closed unexpectedly (before the connection to the final peer was established)
QAbstractSocket::ProxyConnectionTimeoutError
16
The connection to the proxy server timed out or the proxy server stopped responding in the authentication phase.
QAbstractSocket::ProxyNotFoundError
17
The proxy address set with setProxy() (or the application proxy) was not found.
QAbstractSocket::ProxyProtocolError
18
The connection negotiation with the proxy server because the response from the proxy server could not be understood.