在Android应用程序中管理活动树

Question

I think I didn't clearly asked this question before (because I didn't get the answer that I needed) and it was a mistake to post this version here , so I'll try one last time.

I have a big tree of activities where there is one root-activity with 6 list items, each item leads to its own activity with its own list of items, etc. One generation of the tree can be displayed in one activity. So there is only 1 activity for the root and 1 for all of its children(just different list items which are displayed during the runtime depending on the previously chosen item). Navigation obviously should work in both directions - forward(get closer to the leaves of the tree) and backwards(get closer to the root). Hops between generations are also possible(eg we can jump from the 1 generation straight to the 3 and backwards). I think that creating intents every time user goes to another activity is not reasonable. Is there any pattern or good practice to manage multiple activities like in this case? Maybe in each activity should be stored a static class which returns its intent or another management class created?

Answer 1

In Android activities are managed on a (back-) stack. Which means you can start a new activity and it is pushed onto the stack and is the activity shown. When going back via finish() this top activity is popped from the stack.

Stacks and trees work together quite well. When you move around in a tree you can keep the path to the root on a stack. This way managing trees of activities is what Android is actually made for.

Going down in the tree means calling the activity of the child node. Going up again is done by simply finishing your activity. You automatically appear at the activty one level up in the tree.