title: Android Application->onCreate() not called when reopen app
body: <pre><code>public class MyApplication extends Application{
  
  @Override
  public void onCreate()
  {
      super.onCreate();
      Log.d("*******:", "onCreate");
  }}
  </code></pre>
  
  <hr>
  
  <pre><code>public class MainActivity extends ActionBarActivity{
  
  @Override
  protected void onCreate(Bundle savedInstanceState)
  {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  }}
  </code></pre>
  
  <hr>
  
  <pre><code>&lt;application
      android:name=".MyApplication"
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" &gt;
      &lt;activity
          android:name=".MainActivity"
          android:label="@string/app_name" &gt;
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.MAIN" /&gt;
  
              &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
      &lt;/activity&gt;
  &lt;/application&gt;
  </code></pre>
  
  <p>When this Application is opened first time, the onCreate() method in MyApplication has been called,but when I finish the Activity(Press the Back Button), then reopen the app,I found the onCreate() method in MyApplication NOT been called.</p>
  
  <p>And it is weird that if I "kill" the app in system background,then reopen it, I found the onCreate() method could be called again.</p>
  
  <p>I don't know why,and I want to get the action when user reopen my application,could anyone help? Thanks!</p>