Activity, AppCompatActivity, FragmentActivity, and ActionBarActivity: When to Use Which?
I thought Activity was deprecated
No.
So for API Level 22 (with a minimum support for API Level 15 or 16), what exactly should I use both to host the components, and for the components themselves? Are there uses for all of these, or should I be using one or two almost exclusively?
Activity
is the baseline. Every activity inherits from Activity
, directly or indirectly.
FragmentActivity
is for use with the backport of fragments found in the support-v4
and support-v13
libraries. The native implementation of fragments was added in API Level 11, which is lower than your proposed minSdkVersion
values. The only reason why you would need to consider FragmentActivity
specifically is if you want to use nested fragments (a fragment holding another fragment), as that was not supported in native fragments until API Level 17.
AppCompatActivity
is from the appcompat-v7
library. Principally, this offers a backport of the action bar. Since the native action bar was added in API Level 11, you do not need AppCompatActivity
for that. However, current versions of appcompat-v7
also add a limited backport of the Material Design aesthetic, in terms of the action bar and various widgets. There are pros and cons of using appcompat-v7
, well beyond the scope of this specific Stack Overflow answer.
ActionBarActivity
is the old name of the base activity from appcompat-v7
. For various reasons, they wanted to change the name. Unless some third-party library you are using insists upon an ActionBarActivity
, you should prefer AppCompatActivity
over ActionBarActivity
.
So, given your minSdkVersion
in the 15-16 range:
If you want the backported Material Design look, use
AppCompatActivity
If not, but you want nested fragments, use
FragmentActivity
If not, use
Activity
Just adding from comment as note: AppCompatActivity
extends FragmentActivity
, so anyone who needs to use features of FragmentActivity
can use AppCompatActivity
.
Activity
is the base class of all other activities, I don't think it will be deprecated. The relationship among them is:
Activity
<- FragmentActivity
<- AppCompatActivity
<- ActionBarActivity
'<-' means inheritance here. The reference said ActionBarActivity
is deprecated, use AppCompatActivity
instead.
So basically, using AppCompatActivity
is always the right choice. The differences between them are:
-
Activity
is the basic one. - Based on
Activity
,FragmentActivity
provides the ability to useFragment
. - Based on
FragmentActivity
,AppCompatActivity
provides features toActionBar
.
2019: Use AppCompatActivity
At the time of this writing (check the link to confirm it is still true), the Android Documentation recommends using AppCompatActivity
if you are using an App Bar.
This is the rational given:
Beginning with Android 3.0 (API level 11), all activities that use the default theme have an ActionBar as an app bar. However, app bar features have gradually been added to the native ActionBar over various Android releases. As a result, the native ActionBar behaves differently depending on what version of the Android system a device may be using. By contrast, the most recent features are added to the support library's version of Toolbar, and they are available on any device that can use the support library.
For this reason, you should use the support library's Toolbar class to implement your activities' app bars. Using the support library's toolbar helps ensure that your app will have consistent behavior across the widest range of devices. For example, the Toolbar widget provides a material design experience on devices running Android 2.1 (API level 7) or later, but the native action bar doesn't support material design unless the device is running Android 5.0 (API level 21) or later.
The general directions for adding a ToolBar are
- Add the v7 appcompat support library
- Make all your activities extend
AppCompatActivity
- In the Manifest declare that you want
NoActionBar
. - Add a
ToolBar
to each activity's xml layout. - Get the
ToolBar
in each activity'sonCreate
.
See the documentation directions for more details. They are quite clear and helpful.