Why is onDestroy() called after onResume() when using back-button
<p>When I start my android-activity first <code>onCreate()</code> is called, then <code>onResume()</code>.</p>

<p>When I then press the back-button to return to the home-screen and tap the app-icon again, first <code>onCreate()</code> is called, then <code>onResume()</code> and then <code>onDestroy()</code>.</p>

<p>My app is still active then, but doing some action result in error since <code>onDestroy()</code> sets a few members to null.</p>

<p>Why is that?</p>

<p><strong>Update:</strong> When I wait 30 seconds after pressing back everything works fine. I'm not doing anything heavy in onDestroy except setting a few variables to null and <code>.interrupt()</code>ing a background-thread.</p>
