What is the difference between
android.support.v4.app.Fragment, and what are the circumstances in which each should be used?
android.support.v4.app.Fragment is the Fragment class in the android support library, which is a compatibility package that allows you to use some of the newer features of Android on older versions of Android.
android.app.Fragment is the Fragment class in the native version of the Android SDK. It was introduced in Android 3 (API 11).
If you want to make your app use fragments, and want to target devices before API 11, you must use
android.support.v4.app.Fragment. However, if you’re only targeting devices running API 11 or above, you can use
Edit: the OS-contained
android.app.Fragment is now deprecated (as of API level 28), and everyone should move to using the support library implementations.
As of 2018:
This class was deprecated in API level 28.
Use the Support Library
Fragmentfor consistent behavior across all devices and access to Lifecycle.
So support fragments (
android.support.v4.app.Fragment) should be used everywhere instead of native fragments(
All the apps I write need to support right back to Android 2.3 and this is the easiest way to do it.
If you’re supporting 11+ then stick to
If your application is targeted for API 11 or above, You can use
android.app.Fragment and your APK file will be smaller.
Otherwise, add the
android.support.v4.app.Fragment library to your project in order to support older android API versions (Android 3.x).
android.support.v4.app.Fragment is a library that you can use to get backwards-compatibility for older API version.
Fragments were added on API level 11 (along with other features) you should include that library to extend those function to pre-API 11 devices. That is a useful library and I suggest having a look at ActionBarSherlock, which extends the action bar to pre-API v11 devices.
If your application is targeted for API 11 or above level, You can use android.app.Fragment and it will reduce the APK size.
Otherwise use android.support.v4.app.Fragment