Android Bundle = .NET Session[]?

The description of Android Bundle says:

Bundles are Android's way of maintaining and passing program state. The system is constructed around the assumption that any program (characterized by a collection of activities) may be preempted at any time, and if the system resources are low, may be subsequently killed. To handle this difficulty, a Bundle called an ic开发者_如何学运维icle is saved whenever the activity is preempted.

Like with a hash table or dictionary, items added to the Bundle are given a key which is later used to retrieve the data (using data-type specific methods like getCharacter(String key) and getParcelable(String key)). When you are creating activities, be sure to save any important state information into the icicle given to onFreeze so that you can restore your program in onCreate if it is killed while suspended.

Is Bundle the same as Session[] in .NET?

Not exactly, no.

In .NET the you can access the State object from anywhere at any time, and you will be pretty sure that objects that you have placed inside of it will still be there when you are calling it. The session expires though, and unless you have saved anything in your viewstate, that data becomes lost.

Android uses Bundles because of the nature of the OS, it will keep your application "alive" in the background where state is preserved, but if it deems that your application is idle and that it can be killed, it will kill your app to free up resources. Before your app process is killed it will call onFreeze() (now renamed to onSaveInstanceState()) which will give you the opportunity to save data to the Bundle that will be passed to onCreate the next time your application starts up (so you can initialize your screen again).