prevent imageView reloading when change of orientation in android

I read somewhere in this forum that android starts the activity all over again after changing the orientat开发者_开发技巧ion of the phone, is it the case? if so, is there anyway that I could prevent it, there are some images in my activities that is downloaded from the internet when the activity starts, I only want them to download once. Or do I need a cache for all of the bitmaps? By the way, it turns out that ListView would not be reloaded, right?

---

put this as attribute on the activity u use and every other you want, in the application manifest

android:configChanges="orientation|keyboardHidden"