在更改屏幕方向时重置操作

I've got a little app with some fragments etc. Now everytime I change the orientation of my screen, the action is restarted, meaning that the input gets lost if you turn your device. How can I prevent this? In addition I'd like to keep the possibility to change my orientation and the app changes with it, I just want to keep the content in.I've got a little app with some fragments etc.