android, starting and exiting activities

I have not really understood the handling of activities and the stack. I have 3 activities, A - a splashcreen, B- a menu and C another Activity. I start the splash and exits it after a while when the menu is started. In code I handle them all like this:

startActivity(new Intent(this, ContactInfoMenu.class));
        finish();

Now, if I start the app and goes A-B-C, when I hit "B开发者_运维技巧ack" in C screen I jump back to B-the menu. Another "Back" exits the application, just like I want. BUT .. if I go A-B-C-B-C - the "Back" button in C screen exits the whole app instead of getting me back to the B screen?

Why is that? It does like that in all my "subscreens", I can only enter them once, if I enter them a second time the "Back" button exits the app. And I have not tried to catch the "Back" action anywhere? Shouldn't I always call "finish()" when I start a new activity?

Regards

Finish is good for leaving the current activity and going back to the previous one. Otherwise, try to avoid calling finish() if you can help it.

There are a set of flags that you can pass when you start an activity that do a better job of determining how that activity behaves on the stack. These include:

• FLAG_ACTIVITY_NO_HISTORY - your activity will not remain on the stack after another activity covers it.
• FLAG_ACTIVITY_CLEAR_TOP - a good way to pop off a bunch of activities when you need to "go back" to a certain activity.

Many of these flags can be set in the manifest. Reading up on them will give you a better idea about "The Android Way".

Basically, You don't need to call finish() every time you go to another activity. If system is low on memory it will close your activity instance by itself.

finish() is more often used when yor are inserting some information in one page and then moving on to some other page. In that case, you might need to fininsh your first activity. But in case where you need to shuffle between views, you must not use a finish() function, because it will cause the whole application to finish. Try using back button of your own in your views to shift between activities, where you can move to any other activity of your application or even to the Main Screen.