What Qt’s DefaultProxy Inherits
Choose inherited, direct or explicit proxy behavior for Qt network objects without treating DefaultProxy as a synonym for a system setting.
Qt’s DefaultProxy means that the object inherits the application’s proxy choice. It does not mean “connect directly,” and its name alone does not promise that a particular operating-system setting was discovered.
| Choice | Intent |
|---|---|
| DefaultProxy | Use the application-level policy |
| NoProxy | Request a direct connection |
| An explicit HTTP or SOCKS proxy | Use the supplied endpoint and proxy type |
For example, an application can establish a shared HTTP proxy:
QNetworkProxy::setApplicationProxy(
QNetworkProxy(QNetworkProxy::HttpProxy, "proxy.example", 8080));An HTTP address from the HTTP proxy list can supply the example host and port for permitted public requests without proxy authentication. A network manager using the inherited choice can then follow that policy. A manager given an explicit endpoint or NoProxy has a deliberate local selection instead.
When the application should follow the operating system, use the supported QNetworkProxyFactory system-configuration interface. Keep that discovery decision separate from the enum value used by a particular socket or manager.
Configure the choice before the relevant connection. Qt documents that changing proxy settings on an already connected socket does not move that connection to the new endpoint.