Implement software update
I want to add a software automatic update feature to my program. I wonder if there is a common solution already, or I have to build it myself.
is there any tool or library similar to Qt installer framework?
Some spark may come to you from http://winsparkle.org/. It also available GitHub. I'm not aware anything developed for Qt.
There's also KDAB's KD Tools which contains an updater framework
You may also consider "UpdateNode":http://www.updatenode.com/ or "Flexera":http://www.flexerasoftware.com/products/entitlement-management/flexnet-connect/.