On pressing the back button, I'd like my application to go into the stopped state, rather than the destroyed state.
In the Android docs it states:
I think there must be three possibilities...
Edit: I know about services and am using one in the application to which this problem is related. This question is specifically about putting the Activity into the stopped state rather than the destroyed state on pressing the back button.
-Answers by Dave Webb
try to override void
More details
In the Android docs it states:
...not all activities have the behavior that they are destroyed when BACK is pressed. When the user starts playing music in the Music application and then presses BACK, the application overrides the normal back behavior, preventing the player activity from being destroyed, and continues playing music, even though its activity is no longer visibleHow do I replicate this functionality in my own application?
I think there must be three possibilities...
- Capture the back button press (as below) and then call whatever method(s) the home button calls.
@Override public boolean onKeyDown(int keyCode, KeyEvent event) { if ((keyCode == KeyEvent.KEYCODE_BACK)) { Log.d(this.getClass().getName(), "back button pressed"); } return super.onKeyDown(keyCode, event); }
- Capture the back button press and then spoof a home button press.
- Capture the back button press, then start an Activity of the home screen, effectively putting my application's Activity into the stopped state.
Edit: I know about services and am using one in the application to which this problem is related. This question is specifically about putting the Activity into the stopped state rather than the destroyed state on pressing the back button.
- BobbyShaftoe(from stackoverflow)
Solution:-
Most of the time you need to create a Service to perform something in the background, and your visible
A simpler approach is to capture the
NOTE: as pointed out by Dave below Android 2.0 introduced a new
-Answers by foxxtrot
Activity
simply controls this Service
.
(I'm sure the Music player works in the same way, so the example in the
docs seems a bit misleading.) If that's the case, then your Activity
can finish
as usual and the Service
will still be running.A simpler approach is to capture the
Back
button press and call moveTaskToBack(true) as follows:@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
moveTaskToBack(true);
return true;
}
return super.onKeyDown(keyCode, event);
}
I think the preferred option should be for an Activity to finish
normally and be able to recreate itself e.g. reading the current state
from a Service if needed. But moveTaskToBack
can be used as a quick alternative on occasion.NOTE: as pointed out by Dave below Android 2.0 introduced a new
onBackPressed
method, and these recommendations on how to handle the Back button.-Answers by foxxtrot
Or
If you want to catch the Back Button have a look at this post on the Android Developer Blog. It covers the easier way to do this in Android 2.0 and the best way to do this for an application that runs on 1.x and 2.0.
However, if your Activity is Stopped it still may be killed depending on memory availability on the device. If you want a process to run with no UI you should create a
However, if your Activity is Stopped it still may be killed depending on memory availability on the device. If you want a process to run with no UI you should create a
Service
. The documentation says the following about Services:A service doesn't have a visual user interface, but rather runs in the background for an indefinite period of time. For example, a service might play background music as the user attends to other matters, or it might fetch data over the network or calculate something and provide the result to activities that need it.These seems appropriate for your requirements.
-Answers by Dave Webb
Or
try to override void
onBackPressed()
defined in android.app.Activity class.More details
On pressing the back button, I'd like my application to go into the stopped state, rather than the destroyed state.
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