Override Android Back Button

问题

A little info as to why I am attempting to do this: I am using ActivityGroups to open an activity from a tabHost activity and have that new activity stay under the tabs. That part i've got. But when in that new activity, if I use the back button it takes me right out of the tabs activity so I have to click a few times to get back to where I was.

Is there a way to set the back button to go to a specific activity rather than killing the current activity window?

回答1:

In general, I would advise against that because it breaks the UX. The user expects the back button to kill the entire window, especially since you are using the tabhost. To the user, the entire bunch (tabs and all) is a single activity that he wants to exit when he hits the back button.

If you still want to do it, refer to #onBackPressed(). It is called when the activity has detected the user's press of the back key. The default is to finish the activity, but you can make it do whatever you want. I advise care and caution.

You might find some inspiration from here.

回答2:

I believe you should be able to do something like this:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if ((keyCode == KeyEvent.KEYCODE_BACK)) {
        // start new Activity here
    }
    return super.onKeyDown(keyCode, event);
}

But overriding the expected functionality of the back button is not advisable.

来源：https://stackoverflow.com/questions/7550505/override-android-back-button