Why onDestroy inActivity is not called after calling the finish () function in ActivityB

Question

The following process is easy to understand and reproduce, but leads to an error:

• activityA starts action B in its onCreate() method
• activityB is created and I call finish() on my onResume () method
• activityB onDestroy() is called
• activityA onResume() is called
• and here, in activityA, I press the menu button to call finish() - or press the return key.
• activityA is deleted, but onDestroy() NOT called and A is still alive (adp shell dumpsys "myPackageName" indicates too many live actions).

code

 <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="gleroy.com.algo"> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme"> <activity android:name=".activity.MainActivity" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name="gleroy.com.algo.activity.FakeA" android:label="@string/app_name"></activity> <activity android:name="gleroy.com.algo.activity.FakeB" android:label="@string/app_name"></activity> </application> </manifest> 

Action A:

 public class FakeA extends Activity { private final static String TAG = FakeA.class.getCanonicalName(); @Override protected void onCreate(Bundle savedInstanceState) { Log.d(TAG, "onCreate, taskId :" + getTaskId()); super.onCreate(savedInstanceState); Intent intent = new Intent(FakeA.this, FakeB.class); startActivity(intent); } @Override protected void onResume() { Log.d(TAG, "onResume"); super.onResume(); } @Override protected void onDestroy() { Log.d(TAG, "onDestroy"); super.onDestroy(); } @TargetApi(Build.VERSION_CODES.HONEYCOMB) @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); super.onCreateOptionsMenu(menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.stop_session_menu_item: /* stop and quit */ finish(); return false; } return super.onOptionsItemSelected(item); } } 

Activity B:

 public class FakeB extends Activity { private final static String TAG = FakeB.class.getCanonicalName(); @Override protected void onCreate(Bundle savedInstanceState) { Log.d(TAG, "onCreate, taskId :"+getTaskId()); super.onCreate(savedInstanceState); } @Override protected void onResume() { super.onResume(); Log.d(TAG, "onResume, isFinishing :" + isFinishing()); finish(); } @Override protected void onDestroy() { super.onDestroy(); Log.d(TAG, "onDestroy"); } } 

Action A is launched from MainActivity, which contains a simple button:

  @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent(MainActivity.this, FakeA.class); startActivity(intent); } }); 

So, I know that we cannot be sure what we will call onDestroy() , but here my ActivityA is clearly onDestroy() .

I also noticed that if I use Timer and TimerTask to delay startActivity in ActivityA or finish() in ActivityB, then I no longer have this error.

Here are the events:

• FakeA onCreate, taskId: 154
• Fakea onresume
• FakeA onPause, isFinishing: false
• FakeB onCreate, taskId: 154
• FakeB onResume, isFinishing: false
• Fakea onresume
• Fakeb ondestroy
• end a call or press the return key: FakeA onPause, isFinishing: true

Answer 1

Instead of finish() try finishAffinity() . As far as I know: finish() just destroys the current live Activity and finishAffinity() destroys all active Activities .

Answer 2

The best solution was to simply determine whether it is useful to run Activity FakeB.