Saving programmatically added Views on orientation change?

问题

I'm having trouble with saving Views on orientation change. So here's what's going on for me. I have a class extending HorizontalScrollView that creates a LinearLayout and a button in it's constructor. More buttons are added to the LinearLayout when a button is clicked. When the activity starts, I set the Action Bar to this custom view and it all works just fine, adding and deleting buttons from the LinearLayout. But, here's where the problem starts. If a switch orientation, onCreate is restarted, so a new instantiation of my custom view is created and set to the Action Bar. Therefore, my custom view returns to the beginning when I switch orientation.

How do I persist the view's hierarchy throughout orientation changes?

回答1:

When orientation changes activity is destroyed and recreated.

In your manifest add the following to your activity.

      <activity android:name=".MyActivity"
      android:configChanges="orientation|keyboardHidden|screenSize"
      android:label="@string/app_name">
      //Beginning with Android 3.2 (API level 13), the "screen size" also changes when the device switches between portrait and landscape orientation.
      //add screenSize for api 13 and above.   

Now, when one of these configurations change, MyActivity does not restart. Instead, the MyActivity receives a call to onConfigurationChanged(). This method is passed a Configuration object that specifies the new device configuration.

http://developer.android.com/guide/topics/resources/runtime-changes.html

回答2:

The best way for that much information is to add android:configChanges="orientation" to your activity in the manifest, and it will prevent the destroy and relaunch functionality that Android assumes you want. Truthfully I'd suggest adding that to any activity that doesn't have a different layout file for landscape and portrait mode.

来源：https://stackoverflow.com/questions/15858413/saving-programmatically-added-views-on-orientation-change