线程之间的Qt连接类型：为什么这样做？

While trying to make a multi-camera system work with a different thread handling a different camera, I couldn't get signals and slots working correctly between different threads. I knew something was wrong with the fact that the object sending the signal and the related slot's object were living in different threads, and thus I knew that I probably only had to find an appropriate "connection type" parameter for the connection. Eventually, I ended up discovering that only using Qt::DirectConnection would make everything work as it should.While trying to make a multi-camera system work