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POProblems understanding the life cycle when screen goes off and on
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copied!<p>Information: My device is a Nexus One with 2.2 and I have tested two projects, one on 1.5 and one on 2.1.</p> <p>Problem: I have trouble to understand the life cycle of my application when the screen is turned off and on.</p> <p>Here is my output</p> <pre><code>// activity starts 08-04 17:24:17.643: ERROR/PlayActivity(6215): onStart executes ... 08-04 17:24:17.643: ERROR/PlayActivity(6215): onResume executes ... // screen goes off 08-04 17:24:28.943: ERROR/PlayActivity(6215): onPause executes ... 08-04 17:24:32.113: ERROR/PlayActivity(6215): onStop executes ... 08-04 17:24:32.113: ERROR/PlayActivity(6215): onDestroy executes ... 08-04 17:24:32.983: ERROR/PlayActivity(6215): onStart executes ... 08-04 17:24:32.983: ERROR/PlayActivity(6215): onResume executes ... 08-04 17:24:32.983: ERROR/PlayActivity(6215): onPause executes ... // screen goes on 08-04 17:24:47.683: ERROR/PlayActivity(6215): onResume executes ... // lock removed 08-04 17:24:56.943: ERROR/PlayActivity(6215): onPause executes ... 08-04 17:24:59.663: ERROR/PlayActivity(6215): onStop executes ... 08-04 17:24:59.663: ERROR/PlayActivity(6215): onDestroy executes ... 08-04 17:25:00.943: ERROR/PlayActivity(6215): onStart executes ... 08-04 17:25:00.943: ERROR/PlayActivity(6215): onResume executes ... </code></pre> <p>I am totally confused. Why restarting the activity when the screen goes off? And why stop and restarting it again when the screen was already on and only the lock was removed?</p> <p>To make sure I haven't done anything wrong, I created a new project with only this activity. The output is identically...</p> <pre><code>public class LifeCycleTest extends Activity { private final static String DEBUG_TAG = "FirstLifeLog"; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Log.e(DEBUG_TAG, "onCreate executes ..."); setContentView(R.layout.main); } protected void onRestart() { super.onRestart(); Log.e(DEBUG_TAG, "onRestart executes ..."); } protected void onStart() { super.onStart(); Log.e(DEBUG_TAG, "onStart executes ..."); } protected void onResume() { super.onResume(); Log.e(DEBUG_TAG, "onResume executes ..."); } protected void onPause() { super.onPause(); Log.e(DEBUG_TAG, "onPause executes ..."); } protected void onStop() { super.onStop(); Log.e(DEBUG_TAG, "onStop executes ..."); } protected void onDestroy() { super.onDestroy(); Log.e(DEBUG_TAG, "onDestroy executes ..."); } } </code></pre> <p>Does someone have an idea?</p> <p>Update from today (dont understand why it behaves not like last time, maybe more free resources?)</p> <pre><code>// activity starts 08-09 12:14:03.122: ERROR/FirstLifeLog(15406): onCreate executes ... 08-09 12:14:03.132: ERROR/FirstLifeLog(15406): onStart executes ... 08-09 12:14:03.132: ERROR/FirstLifeLog(15406): onResume executes ... // screen off 08-09 12:14:07.412: ERROR/FirstLifeLog(15406): onPause executes ... // screen on 08-09 12:14:11.722: ERROR/FirstLifeLog(15406): onResume executes ... // no log for removed screen lock </code></pre>

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