Android：关于Configurations

The following list describes the conﬁ guration changes you can specify:
❑ orientation The screen has been rotated between portrait and landscape.
❑ keyboardHidden The keyboard has been exposed or hidden.
❑ fontScale The user has changed the preferred font size.
❑ locale The user has chosen a different language setting.
❑ keyboard The type of keyboard has changed; for example, the phone may have a 12 keypad
that ﬂ ips out to reveal a full keyboard.
❑ touchscreen or navigation The type of keyboard or navigation method has changed. Neither of these events should normally happen.
You can select multiple events to handle by separating the values with a pipe (|).
The following XML snippet shows an activity node declaring that it will handle changes in screen orientation and keyboard visibility:
android:label=”@string/app_name”
android:theme=”@style/TodoTheme”
android:configChanges=”orientation|keyboard”/>
Adding this attribute suppresses the restart for the speciﬁ ed conﬁ guration changes, instead, triggering
the onConfigurationChanged method in the Activity. Override this method to handle the conﬁ guration changes using the passed-in Configuration object to determine the new conﬁ guration values, as
shown in the following skeleton code. Be sure to call back to the super class and reload any resource
values that the Activity uses in case they’ve changed.
@Override
public void onConfigurationChanged(Configuration _newConfig) {
super.onConfigurationChanged(_newConfig);
[ ... Update any UI based on resource values ... ]
if (_newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {
[ ... React to different orientation ... ]
}
if (_newConfig.keyboardHidden == Configuration.KEYBOARDHIDDEN_NO) {
[ ... React to changed keyboard visibility ... ]
}
}
When onConfigurationChanged is called, the Activity’s Resource variables will have already been
updated with the new values so they’ll be safe to use.
Any conﬁ guration change that you don’t explicitly ﬂ ag as being handled by your application will still
cause an application restart without a call to onConfigurationChanged

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